Convert>Filename-filename: Placeholders?

I have only just discovered MP3TAG, and I'm greatly impressed-- it's right up there with foobar2k and that's the highest praise I can think of.

Unfortunately, I'm an old man with a shrinking brain, and I cannot get my head around placeholders in Convert>Filename - filename.

I'm unable to work out the relationship of placeholder pattern to filename to the example given:

Old filename pattern: (%1 - %2) %3 %4 %5 (%6)
Old filename: (Artist - Album) 01 EXAMPLE 2004 (COMMENT).mp3

New filename pattern: %5 (%1 - %2) Example '['%6']'
New filename: 2004 (Artist - Album) Example [COMMENT].mp3

I would be most grateful if you could provide as many varied examples as you have time for, so I have a better chance to understand how these placeholders work.

I'm trying to convert the a load of filenames which currently have tracknumbers at the end instead of the start (and also remove artist name and all spaces & dashes) - a single example would be:
ABBA - Gimme! Gimme! Gimme! (A Man After Midnight) - 14.mp3
which I'd like to convert to
14Gimme!Gimme!Gimme!(AManAfterMidnight).mp3

I think I can manage the removals, but without a proper understanding of placeholders, cannot move the track number 14 to the head of the filename.

However if you only give me a single example of how to fix the above, I may still be unable to figure out how placeholders work. And then perhaps you might consider adding a few more examples to the Converter page of your excellent help file, to assist dim people like me...

Old: %1 - %2 (%3) - %4
New: $replace(%4%2(%3), ,)

(I use the replace function here to remove all spaces.)

With the placeholders you try to rebuild the structure of the file name.
First you deconstruct it into different parts with separators like space, dash, parenthesis ...
Then build it again in a new way.

Be aware, that once you have converted a "partable filename" into a somewhat shrinked filename, you will nearly never have a chance later to extract a meaningful part from the filename.

Do you have already inserted tag fields into the mp3 files, which carries the Artist name, Title name, Track number and such other attributes?

If you did so already, then you might be on the safe side, because you will be able to construct whatever filename you want from the tag field's content.

DD.20100514.1823.CEST

Dano; thank you very much for instant and enlightening reply. At first I thought I still needed more examples to fully understand how placeholders work, but now I have the feeling for it...

And it's very pleasing to see how $replace() integrates so easily into the one action

I still believe it might be helpful for slow people like me if there were eventually just one more example in the help section Convert>Filename - filename -- perhaps also integrating a function (such as your solution to my question), which might also help newcomers to MP3tag to appreciate its power and simplicity.

DetlevD; thank you also for the timely warning about the difficulties of deconstructing squashed filenames.
Fortunately in this case I have good tags, but even if I didn't, perhaps I could still recover at least the spaces using Regular Expressions to detect numbers and junctions between lower and upper case.