there is an alias which creates a trigger to substitute the names of pills, wands, etc with their effects (obtained on this forum some branches ago)

this is a string, creating a trigger
#trigger {<@PrepName>} {#sub "<@PrepName> ~[<@PrepEffects>~]"} {PrepSubs} "PrepSubs"

a problem is that a sub command does not take a value of the first variable @PrepName just because there is no any symbol between the start of the string and a variable.
So if you have
PrepName = "aaa"
PrepEffects = "zzz"

then you will have the following output
#sub "@PrepName [zzz]"

But if I change the alias and put any symbol before first variable, a space for example, like:
#trigger {<@PrepName>} {#sub " <@PrepName> ~[<@PrepEffects>~]"} {PrepSubs} "PrepSubs"
^ here

then I get the following output:
#sub " aaa [zzz]"
^ with a space here.

This works that way, but those spaces look bad.
Any ideas how to fix that ?