Camera variable for File out node ?

Hi,
I have a setup that writes the AO pass and some defined objects to a separate file as a post-production aid.
Now, I use a lot of different viewpoints instead of animations, for this I use the ‘render cameras’ script, very handy.
However, is there a way I can fill in a variable in the file output node ?
Something like:
//renders$CAMERANAME\AmbientOcclusionPass.png

??
thanks for any pointers,

wzzl