Assign function key in mail to automate steps

One of my most frequent steps in Apple Mail is moving mail that has been read to different mailboxes. I have, until now, simply dragged the mail to its destination mailbox on the sidebar. But I would prefer to do this using just the keypad. There is a 'Move to...' action on the Messages menu. But there is no pre-defined shortcut. How do I create a shortcut to this function? For example, how could I assign the F14 key to trigger the =move to function?