Wildcard User Aliases

I’m migrating domains and mail services from a previous provider to my MiaB, and I’m curious if I can migrate a particular feature:

At my previous provider, I have a Rule set up: If any mail is received that ENDS in ".user"@mydomain.com, it will automatically forward to "user"@mydomain.com. For example:

amazon.user@mydomain.com
facebook.user@mydomain.com
eBay.user@mydomain.com

…all forward to user@mydomain.com

Is there any way to do this with mail-in-a-box? I know about user tagging (user+tag@mydomain.com) but that wasn’t available at my other provider, so I have a TON of these “xxxx.user” emails that come in. This method allows me to sort messages automatically while keeping this mailbox separate from my catchall mailbox.

Any help would be much appreciated!