Manipulate called controller function name before it is called?

[eluser]TaylorOtwell[/eluser]
Is there a way for me to change the incoming request function name before the function is actually called?

For instance, say the incoming request is to "domain.com/foo/bar", I want to be able to change the "bar" to something else and let CI call the function I give it instead of the "bar" it would usually call.

I've read about the _remap() possibility, but that won't work in my situation. What I want to do is basically setup a post_controller_constructor hook, and if the incoming request is a POST request, append "_post" to the function name CI is going to call. That way, I can have a form post to "domain.com/foo/bar", but the request will be routed to the "bar_post" function. I don't want to have to put _remap() in every controller.

Is there a way to do this?

Thanks!