Forums Scripts & Popups Can create custom variables but can't read them?

Your /set commands work fine; you don't need square brackets or anything in /set. However, you do need some way to force further evaluation when you want to retrieve the value of such variable, and that's square brackets or $eval()
First way:
//echo -s % [ $+ [ $me ] ]

Second way:
//echo -s $eval(% $+ $me,2)
or $eval($+(%,$me),2)