Splitting a long Filename into 2 fields

I have a bunch of mp3s that were previously named with a "compound" file name that supposedly was to indicate the YEAR and TRACK and used the following filename convention:

2016-001 ARTIST TITLE.mp3 (for track 1)
2016-002 ARTIST TITLE.mp3 (for track 2)
2016-003 ARTIST TITLE.mp3 (for track 3), etc.

How do I extract the 3 rightmost characters for the TRACK tag and consequently the leftmost 4 characters for the YEAR tag?

I've tried playing with the "String Functions" such as $right(x,n) but so far no joy.
Wouldn't "$right(%year%,3) give me "001" which can be the Track tag. Any ideas?

Sleepless in California

Use filename > tag :mt_ftt: with:

%year%-%track% %dummy%

Thanks, that will do the job.

In the meanwhile, I kept pounding away and came away with another solution:

Use Filename to Filename:
Old pattern = %1-%2 - %3 - %4

New pattern = %1 %2 - %3 - %4

That gets the filename changed into a pattern that'd I'd prefer to use and at the same time, I would then have no problem creating a TRACK tag with:
%year% %track% - %artist% - %title%"