Not sure where the difficulty is.
"m" & TextStyleAdd ( "2" ; superscript )
works fine for me.
If all your measurements vary in length and units: cm, ft, y, m, etc., then you need to accomadate for those.
I'm sure someone will have a better approach than mine, but you could use the following in new calculated field which you can use in your report:
Left ( measurement ; Length ( measurement ) - 1 ) & TextStyleAdd ( Right ( measurement ; 1 ) ; Superscript )