Hi Sandra,
As far as I understand (from older version of SRM), you do not have the flexibility of creating custom action profile. You have to use the standard one. Very often, we control which smartform to use by coding the logics in BADI BBP_OUTPUT_CHANGE_SF IF you do not wish to change the smartform assigned in the standard action,
You could also try creating a new action and deactivate the standard action. I have not done this before so cannot be sure whether this will work. Hopefully you can try this out and let us know how it goes.
Regards
SF