Alt way to auto-crossfade a selected region?

[rabidelephants]

Hey all, new forum member here. I'm trying to set up some macros to speed up editing, and wondering if there's a key command to auto-crossfade the beginning and end of a selected region, without using the mouse to do the crossfades or highlight beyond the boundaries of the region. Basically, I just want to be able to do the same thing that would happen if I selected a region and hit 'F', except with crossfades instead of fades. Again, this is for a macro, and as such it has to be applicable to any region, so I can't hand-draw the crossfades, but multiple-keystrokes would be okay (something like 'extend selection start/end by nudge amount' - and then hitting F might do the trick?

Thanks so much for any help you can offer!

[Hannibal Lecter]

I hope you're not crossfading edits one by one.