Using SMTP Mail with attachments

I am trying to use SMTP Mail Writer to send multiple files created within the protocol.

It works fine if I specify a file name in the Attachments parameter \\\$(Destination)/Filename1.txt

However, I cannot figure out how to send multiple files using a wildcard such as \\\$(Destination)/File*.txt or \\\$(Destination)/\\\$(Files)

Has anyone accomplished this before?