# Complicated Regex or script sought
**URL:** https://community.mp3tag.de/t/complicated-regex-or-script-sought/6957
**Category:** Support
**Created:** [June 21, 2008, 10:55am UTC](https://community.mp3tag.de/t/complicated-regex-or-script-sought/6957 "2008-06-21T10:55:37Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@RabanePaco](https://community.mp3tag.de/u/RabanePaco)
#### Post date: [June 21, 2008, 10:55am UTC](https://community.mp3tag.de/t/complicated-regex-or-script-sought/6957/1 "2008-06-21T10:55:37Z")
I have an album with the following track names:
String1 Substr1.1
String1 Substr1.2
String1 Substr1.3
String2 Substr2.1
String2 Substr2.2
String3 Substr3.1
etc.
I want to change this into
String1 1. Substr1.1
String1 2. Substr1.2
String1 3. Substr1.3
String2 1. Substr2.1
String2 2. Substr2.2
String3 1. Substr3.1
etc.
So I want to number the parts of each peace. [Of course the numbers are not in the strings, so I can't use these.]
Can I do this with Regular expressions? How?
Or can someone give me a lead how to do this with scripts? Is there a tutorial for scripts?
Thanks!
---
### Author:  [@dano](https://community.mp3tag.de/u/dano)
#### Post date: [June 23, 2008, 7:58am UTC](https://community.mp3tag.de/t/complicated-regex-or-script-sought/6957/2 "2008-06-23T07:58:37Z")
Try
_Action type:_ **Replace with regular expression**
_Field:_ **TITLE**
_Regular expression:_ **^(.+?)\s(.+?).(\d)**
_Replace matches with:_ **$1 $3. $2.$3**
[] case-sensitive comparison
---
### Author:  [@RabanePaco](https://community.mp3tag.de/u/RabanePaco)
#### Post date: [June 23, 2008, 7:33pm UTC](https://community.mp3tag.de/t/complicated-regex-or-script-sought/6957/3 "2008-06-23T19:33:27Z")
As I said: the numbers are not actually part of the strings. They are just there to show the structure of the tracks. Maybe I should have put the strings between brackets, or in quotes.
So you example won't work.
Thanks anyway.
---
### Author:  [@Stevest](https://community.mp3tag.de/u/Stevest)
#### Post date: [June 24, 2008, 10:23am UTC](https://community.mp3tag.de/t/complicated-regex-or-script-sought/6957/4 "2008-06-24T10:23:44Z")
As far as I know it is not possible in action directly, because there is no counter function in there.
But you can do it in a roundabout way in my opinion.
You can use a special placeholder %\_counter% in export scripts. You can create a text file with the required new titles, then you can use that file to change the %title% fields (Textfile - Tag button).
There is a little code for an export script, but I think it is not very good:
```
$loop($left(%title%,$sub($strstr(%title%,' '),1)),1)$loop($left(%title%,$sub($strstr(%title%,' '),1)))$regexp(%title%,^(.+?)\s(.+?),$1 %_counter%. $2)
$loopend()$loopend()
```
Must be a much better solution. I think the $left part can be replaced with $regexp in some way. But it works if the first part of your title (called StringX) doesn't contain any spaces, and the separator between StringX and SubstrX IS a space.
In the two loop part I used the $strstr function, so if the separator is not a space, you can change the parameter ' ' to the desired separator string. (In that case you have to change the $regexp parameter, too).
It works in these examples:
Titles in files:
```
ABBA Dog
ABBA Cats and Mice
Beatles Elephant
Beatles Sharks and Whales
```
The result:
```
ABBA 1. Dog
ABBA 2. Cats and Mice
Beatles 1. Elephant
Beatles 2. Sharks and Whales
```
Anyway, I wonder the regexp version of this script. 🙂
[Help.mte](https://community.mp3tag.de/uploads/default/original/2X/7/70c60a4bcff88b1eb53611005a65f586b14fc39d.mte) (172 Bytes)
---
### Author:  [@RabanePaco](https://community.mp3tag.de/u/RabanePaco)
#### Post date: [June 25, 2008, 12:25pm UTC](https://community.mp3tag.de/t/complicated-regex-or-script-sought/6957/5 "2008-06-25T12:25:26Z")
> [@Stevest](#):
>
> As far as I know it is not possible in action directly, because there is no counter function in there.
> [...] export scripts. You can create a text file with the required new titles, then you can use that file to change the %title% fields (Textfile - Tag button).
That's what I was afraid of.
> [@](#):
>
> If the first part of your title doesn't contain any spaces
Forget it! I think indeed the best bet is to write an external file, edit it and read it back.
Awk could do the job well, I guess. In fact I would need a function that can find the largest initial substring of two strings. No idea if any language has this. Would be nice if the mp3tag script could call awk.
Probably a job for a long winter night.
Still my other question: **anywhere a decent tutorial for the mp3tag scripting language?** Or a couple of representative examples? Is it (like) any existing language? (Although most of these scripting languages are kind of similar).
B.t.w. I think mp3tag is terrific! Unique in its kind. No other tag editor has regexp's! (At least I haven't been able to find one and I looked for a long time before I stumbled onto mp3tag.) I am using it a lot.
Thanks.
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### Author:  [@system](https://community.mp3tag.de/u/system)
#### Post date: [February 9, 2026, 12:21pm UTC](https://community.mp3tag.de/t/complicated-regex-or-script-sought/6957/6 "2026-02-09T12:21:01Z")