> ...but this returns in the number of matching semicolons ("2" in this case). This has been driving me absolutely nuts--any help is appreciated!

$text =~ s/\;(?=(\s[A-Z]{1}[a-z]+,\s([a-zA-z]\.-?)+\,))/\n/g;

does the substitution in $text but returns their number in scalar context.

drop $part and do my @parts = split("\n",$text);