need to change $ char in string

I've tried everything I can think of to change a dallar sign in a string to something else or to split the string on the $ but I can't the the information that comes after the $. Typical string contains: 1.2$General/ms1.zip when I try: $new_string = preg_replace("/\$/", "%", $test_string); or (trying to avoid specifying the $): $new_string = preg_replace("/(\d\.\d{1,2})\D(\w.*$)/", "\1%\2", $test_string); echo "new_string is $new_string"; prints new_string is 1.2 Has anyone solved this problem? Thanx, Bev