Welcome to the Asana Community Forum @Diana_Jaffee!
This isn‘t natively possible in Asana.
Are these tasks created based on a form submission or somebody adds them? If so is always the same person adding them? (Trying to figure out if a specific rule trigger can be set)
Have you considered using custom fields already?
For example when these tasks get added a specific selection is made in the field drop-down which will then trigger rules.
Also here is an existing feedback request thread you might be interested upvoting.
Also have a look at Flowsana