# Padding numerical value in Title or Filename
**URL:** https://community.mp3tag.de/t/padding-numerical-value-in-title-or-filename/15117
**Category:** General Discussion
**Created:** [October 19, 2013, 4:04pm UTC](https://community.mp3tag.de/t/padding-numerical-value-in-title-or-filename/15117 "2013-10-19T16:04:28Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@DavidJ](https://community.mp3tag.de/u/DavidJ)
#### Post date: [October 19, 2013, 4:04pm UTC](https://community.mp3tag.de/t/padding-numerical-value-in-title-or-filename/15117/1 "2013-10-19T16:04:28Z")
So far I've been able to accomplish many changes with MP3Tag, what a great tool! But the last thing I'm having difficulty with is the track # in either the title or filename.
When the CD's were ripped, the track field was padded with a preceeding "0" like this; 01/21, 02/21, etc... The Title however, lists track 01 as Chapter 1, so when the list of tracks are played, Chapter 1 is played, then Chapter 11, then 12, etc... then 2, then 21, etc...
So I'm trying to figure out how to rename only the tracks with a filename (or title) ending with a 1 - 9, so that they end with a 01, 02, etc..
I found a thread talking about the function of "Formatstring: $cutLeft(%\_filename%,17)" which at first I thought could modify to do what I needed, but then decided that it really wasn't the solution without a lot of additional work. Other threads didn't give me much hope either.
I could accomplish this manually, but I have about 300 tracks to modify ☹
Any help would be appreciated!
David...
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### Author:  [@ohrenkino](https://community.mp3tag.de/u/ohrenkino)
#### Post date: [October 19, 2013, 7:19pm UTC](https://community.mp3tag.de/t/padding-numerical-value-in-title-or-filename/15117/2 "2013-10-19T19:19:08Z")
instead of simply using %track% to write the track number use
$num(%track%,2)
So in order to get the filename with padded numbers try the converter Tag-Filename and the mask
%title% - $num(%track%,2)
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### Author:  [@DavidJ](https://community.mp3tag.de/u/DavidJ)
#### Post date: [October 19, 2013, 8:01pm UTC](https://community.mp3tag.de/t/padding-numerical-value-in-title-or-filename/15117/3 "2013-10-19T20:01:27Z")
> [@ohrenkino](#):
>
> instead of simply using %track% to write the track number use
> $num(%track%,2)
>
> So in order to get the filename with padded numbers try the converter Tag-Filename and the mask
> %title% - $num(%track%,2)
Thanks ohrenkino,
That's close, by using that mask the filename changes from "Chapter 1.flac" to - "Chapter 1 - 01.flac".
What I'd like to have is just Chapter 01.flac. Is that possible?
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### Author:  [@poster](https://community.mp3tag.de/u/poster)
#### Post date: [October 20, 2013, 3:44am UTC](https://community.mp3tag.de/t/padding-numerical-value-in-title-or-filename/15117/4 "2013-10-20T03:44:50Z")
> [@DavidJ](#):
>
> What I'd like to have is just Chapter 01.flac. Is that possible?
Instead of trying to change the filename you should build it complete new with "covert Tag-Filename".
That naturally only works, if your filename ist build of filled tags.
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### Author:  [@DetlevD](https://community.mp3tag.de/u/DetlevD)
#### Post date: [October 20, 2013, 6:28am UTC](https://community.mp3tag.de/t/padding-numerical-value-in-title-or-filename/15117/5 "2013-10-20T06:28:39Z")
> [@DavidJ](#):
>
> ... I'm having difficulty with is the track # in either the title or filename. ... So I'm trying to figure out how to rename only the tracks with a filename (or title) ending with a 1 - 9, so that they end with a 01, 02, etc.. ...
> Any help would be appreciated! David...
If you don't want to fully re/create the filename from the values of the tag fields by a fitting format string, then you may use the converter "Tag - Filename" with one format string from the following proposals ...
**$trimRight(%\_filename%,'0123456789 -\_.()#''') $regexp(%\_filename%,'[\d\s\-\_.()#'''']+$',%DUMMY%)**
These format strings may remove more characters from the right edge of the filename as you want it, but I am sure, that you are able to adapt the examples to your need.
Afterwards you can concatenate the track number formatted as you wish, e. g. with a format string like ...
**%\_filename%' '$num(%TRACK%,2)**
In the event that a track number does not exist, then you may apply this format string ...
**$trimRight(%\_filename%,'0123456789')$num(%\_counter%,2)**
... or ...
**$trimRight(%\_filename%,' 0123456789')' '$num(%\_counter%,2)**
DD.20131020.1058.CEST
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### Author:  [@DavidJ](https://community.mp3tag.de/u/DavidJ)
#### Post date: [October 21, 2013, 12:27pm UTC](https://community.mp3tag.de/t/padding-numerical-value-in-title-or-filename/15117/6 "2013-10-21T12:27:51Z")
Thanks DetlevD, that's exactly what I needed!
I had no idea MP3Tag was so powerful, it reminds me of when I was struggling with formulas in Excel...
I ended up combining both statements and was able to batch process large quantities of files at once.
$trimRight(%_filename%,'0123456789 -_.()#''')' '$num(%TRACK%,2)
Thanks again!!
David