Help understanding Perl code.

Well, I found myself trying to fix some Perl code (Ive never done any Perl in my life) and I pinpointed the place where the bug could be. But to be sure I have to know what does a few line of code mean:

$files_lim =~ (/^\d*$/)
$files_lim =~ (/^\d*h$/)
$files_age =~ s/h//

The code where this was pulled out just tries to erase a file thats more than 10 days old.

Thanks in advance.