sub is_match
{
   my $term = shift;
   my $inner = ($term =~ m/^A(.*)Z$/)[0];
   return undef  if (!defined($inner));
   return undef  if $inner eq "";
   return $inner if $inner =~ m/^\s+\S/;
   return undef;
}
prints:.....
AZ:	RESULT=NO MATCH
AZZ:	RESULT=NO MATCH
A SOMETHING Z:	RESULT=" SOMETHING "
ASOMETHINGZ:	RESULT=NO MATCH
A  Z:	RESULT=NO MATCH
A ZZ:	RESULT=" Z"
AAZZ:	RESULT=NO MATCH
AA ZZ:	RESULT=NO MATCH
ZA:	RESULT=NO MATCH