The user choses both the value of $fromUserNumber and of $pat
when $fromUserNumber in a positive integer !
I wanted that when $fromUserNumber == 1
the line will be @simMatches = map{$_ =~ s/$pat/$1/} @simMatches;
when $fromUserNumber == 2
the line will be @simMatches = map{$_ =~ s/$pat/$2/} @simMatches;
and so on.