It does, but that's not the normal usage of split, either. You're saying that you've got a series of records separated by param=anything and that, in addition to returning the things that are separated by that, you also want to return the part in the parentheses.

You can use the =~ operator to apply a regex to a string (which was what I showed you in my example). That is the straightforward way to do what you want. If you have a list or array of strings to apply, you can use map or foreach to set $_ to each of them in turn, and then you don't need the =~ operator, because a regex applies to $_ by default.