Newbie - simple update to title tag

Using Picard for the first time and need some help. I’ve searched the forum and google but still don’t know how to get started on this.

My file names are simple - track number-artist-title.mp3

The tags are already parsed and correct. What I want to do is change the title to track number. title.

I’ve found the place in the preferences to add a Tagger Script but after reading the functions documentation still don’t know how to write this simple script. After having the script, how do I execute it against a folder of music?

Thank you in advance

The default file naming string is

$if2(%albumartist%,%artist%)/$if($ne(%albumartist%,),%album%/,)$if($gt(%totaldiscs%,1),%discnumber%-,)$if($ne(%albumartist%,),$num(%tracknumber%,2) ,)$if(%_multiartist%,%artist% - ,)%title%

Adding a . after $num(%tracknumber%,2) should do what you want. Like this:

$if2(%albumartist%,%artist%)/$if($ne(%albumartist%,),%album%/,)$if($gt(%totaldiscs%,1),%discnumber%-,)$if($ne(%albumartist%,),$num(%tracknumber%,2). ,)$if(%_multiartist%,%artist% - ,)%title%