How to import/paste a list of email addressess into a filter

I want to create a filter to match any of the 20 addresses on my list. Rather than manually repeating the 'add rule' 19 times, I hoped to import all 20 at once. Creating a filter with 'to' and putting a comma separated list there doesn't seem to work; the addresses won't be matched. I can't find a config file to manually edit in my profile directory for filters, or an extension to create this filter. My end-goal is to add this 'blacklist' of my old e-mail addresses that have been leaked to a spam filter. These messages already end up in my spam folder by a rule at my provider, but I want to mark them as spam too, so I can sort through the spam folder more easily to find false positives. Thanks in advance!