$text = 'A0 peter Z0 ...  A42 peter, paul and mary Z42 ... A99 mary Z99';
 
my @and_matches =( $text =~
			   m/
					A(\d+)[^Z]*
					(
						(?=mary)
						[^Z]*
						peter
					|
						(?=peter)
						[^Z]*
						mary
					)
					[^Z]*Z
				/xg );
 
print "@and_matches \n";
__END__
42 peter, paul and mary