lol, come again in plain english this time please?
I dont know what you mean by you want it to input ?
If you want to replace {\bla} with someother text just use $replacex(%text,{\bla},some other text)
If you need to do something else for each occurance of it in a string then
var %i = $pos(%text,{\bla},0)
while (%i) {
; your code here , $pos(%text,{\bla},%i) well be the location of an occurance of {\bla} in the string, as %i counts down its doing the last occurance first
dec %i
}