Is it possible through the API to give it some wikitext and get in return the same wikitext where {{subst:}} and {{safesubst:}} have been replaced, as they would be when saving an edit ?

In WPCleaner, I want to be able to insert things like current date, so I'm currently inserting things like {{safesubst:CURRENTMONTHNAME}} but as they don't work inside <ref> tags, I'd prefer to expand then myself rather than relying on the action=edit to do it.

Nico