[RP] Launching console apps with command completion

[Carlos Pita]

For what I'm able to see this seems to be impossible, but just in case
I'm missing something obvious I'm asking it anyway.

How can I get shell command completion (just like with !) for a custom
prefix as urxvt -e ? As it's evident from the question I want to be
able to launch console applications the same that I launch x ones. The
following doesn't provide completion:

bind P colon exec urxvt -e

I can't figure out how to get it without patching the sources.

Thank you in advance
--
Carlos