zerow, I do not understand what you are telling me, ...
therefore I made an example action group script ...
to demonstrate how to sort number strings in the range from '01' to '99'.
Action #1
Actiontype 5: Format value
Field ______: LIST_CURRENT
Formatstring: '04|21|69|99|17|01|38|78'
Action #2
Actiontype 5: Format value
Field ______: LIST_ORDERED
Formatstring: '01|02|03|04|05|06|07|08|09|10|11|12|13|14|15|16|17|18|19|20|
21|22|23|24|25|26|27|28|29|30|31|32|33|34|35|36|37|38|39|40|
41|42|43|44|45|46|47|48|49|50|51|52|53|54|55|56|57|58|59|60|
61|62|63|64|65|66|67|68|69|70|71|72|73|74|75|76|77|78|79|80|
81|82|83|84|85|86|87|88|89|90|91|92|93|94|95|96|97|98|99'
Action #3
Actiontype 5: Format value
Field ______: LIST_RESULT
Formatstring: $regexp($regexp($regexp(%LIST_ORDERED%,$regexp(%LIST_ORDERED%,'(?>('%LIST_CURRENT%'))',),),'|+','|'),'|$',)
End Action Group Test2015#20150617.Example.Sort.01to99 (3 Actions)
... which gives ...
LIST_RESULT = 01|04|17|21|38|69|78|99
Test2015_20150617.Example.Sort.01to99.mta (535 Bytes)
DD.20150617.1836.CEST
Note: Regular expression has been changed ... see there ...
Moving part of TITLE to GENRE
DD.20150626.1116.CEST
Test2015_20150617.Example.Sort.01to99.mta (535 Bytes)