How to add "/ " to track field?


I am now in the process of transferring all my vinyl to pc, long job..........
I will be converting filename - tag using:

                         %artist% - %album% - %track% - %title%

The track will be 1 of 1, 1 of 2 etc.
As I use Itunes, the "of " will need to be replaced with a "/ " ( which can't be used in a filename), in the tag track field.
Is there a way this can be done other than manually.
I've only been using Mp3tag for a couple of days so excuse me if I've missed something obvious.
Oh, by the way Mp3tag is brilliant.


To convert a string from '1 of 2' to '1/2' you may create an Action using the tag-field-formatting mode.
Field: TRACK
Formatstring: $replace(%TRACK%,' of ','/')



Thanks a lot DetlevD. Worked like a charm.