Custom “Mark us junk” shortcut for multiple emails.

In WLM you can select an email and "Mark [it] us junk" using Ctrl+Alt+J. Unfortunately this works per single email.

Question: Is there already, or can a custom shortcut be created to select multiple emails at once and "Mark [them] us junk"?

Reason: Selecting every single email & repeating this task one by one is tedious, time-consuming & counterproductive.