Routing Question

[eluser]gungbao[/eluser]
Dear CI-Lovers

I have a question regarding an elegant solution about "routing".

Think about my app as:

controllerA/actionA
controllerA/actionB

controllerB/actionA
...

Do you see a simple and out-of-the box routing definition to have
e.g.

.tld/676787

rransparently routed on
controllerA/actionA/676787

without any redirection. do I have to use mod_rewrite or can I do this in CI itself.

Your hint is higly appreciated,
greetings
chris