You can probably try sub string and concatenation something like below not sure on the syntax
FIx (@match (alpha) )
I tired it but its giving me error : attempt to cross a null member in function [@X]
not sure what is this error
Can you paste your script
in fact it worked.. its only giving error when there are no corresponding accounts..
like : if Alfa is not having corresponding Beta accounts or vice versa its giving error, else script is good ..