Well, you probably did not look too thoroughly, I guess. A similar problem is featured in the FAQs:
/t/967/1
You do not quite exactly state, where you want to see this information.
- do want to rename the filename? then use the Converter Tag-Filename with the mask
%track% - %title%
If you want to modify the tag TITLE then resort to the FAQ-link as stated above, but format the tag (field) %title% with the string
$num(%track%,2) - %title%