best way to do this would be to assign it first with a variable.
if you want to select it manually use:
setvar $yourvar = @
assign $yourvar /dir /groups etc.
if you want to pick using user input use:
setvar $yourvar = (which effect number?)
assign effect $yourvar /dir /groups etc.
if you want to use it in a cmd with effect lines specified (1.effect.line) then i'd recommend doing it the user input way so you avoid the word 'effect' in your variable.
i.e. you can't assign 1.effect 419.2 but you can assign effect 1.$yourvar.2
Kai Colucci
VX / LX programmer
Miami, FL