$regexp(%_directory%,.+(\d).*,$1)
That's what I'm using. It's simple but effective. It gives you the last number (single digit) of the directory name. That works almost for all sorts of folder naming schemes.
Wow- nothing like bring an eight year old thread back!
Thank you, that works nicely. It is so elegant once you know but it just didn't occur to me 
this one with the condition, when the foldername contains "cd[number]", "CD[number]", "disc[number]" or "DISC[number]":
$if($and($isdigit($regexp(%_directory%,.+(\d).,$1)),$or($grtr($strstr($lower(%_directory%),'cd'),0), $grtr($strstr($lower(%_directory%),'disc'),0))),$regexp(%_directory%,.+(\d).,$1),)
Returns this expression the same result?
$regexp(%_directory%,'.*(?:cd|disc|disk)\s*0*(\d+).*','$1',1)resp.
$if($neql($regexp(%_directory%,'.*(?:cd|disc|disk)\s*0*(\d+).*','$1',1),%_directory%),$regexp(%_directory%,'.*(?:cd|disc|disk)\s*0*(\d+).*','$1',1),)... or ...
$if($eql($regexp(%_directory%,'.*(?:cd|disc|disk)\s*0*(\d+).*',,1),),$regexp(%_directory%,'.*(?:cd|disc|disk)\s*0*(\d+).*','$1',1),)DD.20140705.1230.CEST
Edit. Suppress leading zeroes.
DD.20140705.1852.CEST
nearly...
these are my test-folders:
a cd01 (test)
b disc02 (test)
cd 03 (test)
d disc 04 (test)
e keine disc
the first expression also creates 'eine' for the last folder, rest in two-digits (with a leading zero)
the second expression works nearly correct (no discnumber for the last folder), but the rest in two-digits (with a leading zero)
I have changed my formatstring in order to suppress leading zeroes, ...
now both formatstrings give nearly the same result.
Note: Prepare your formatstring also for discnumbers greater than 9.
Here is an export script with test cases ...
Test.20140705.ExtractCDNumber.mte (5.76 KB)
DD.20140705.1900.CEST
Test.20140705.ExtractCDNumber.mte (5.76 KB)
thx, now i've two alternatives 