help with conditional copy %track% to %discnumber%

here's what i'm trying to accomplish:

if %track% contains "-" then i want to copy %track% to %discnumber%

for example, many tracks are numbered like this:

any help would be greatly appreciated, i'm sure this is simple, i'm just having trouble figuring it out on my own. thanks

i seem to have accomplished it with with the following "guess value action"

Source format

Guessing pattern

alternative methods to accomplish it still welcome

Do you really want to copy the whole of TRACK into DISCNUMBER? Or just the leading "1"?
Anyway: it would be easiest to apply a filter like
%track% HAS "-"
If you then want to split the field then an action of the type "Import tag-field (guess values)" for TRACK and the mask
would move the 1 (or any other number in front of the hyphen) to DISCNUMBER.

If you only want to copy then run a simple "Format tag-field" action for DISCNUMBER with the format string %track%

well, yes, just the leading "1", but for simplicity i figured i could clean it up after the copy using "replace with regular expression"