chain of filters

I have my Laserjet 5N running nicely with Cups and Foo-matic. I however want to 
implement a simple kind of accounting. In order to do this i need to run an 
extra *cupsFilter. This filter will not do anything with the printjob itself, 
it will just log the user. Based on the 7 arguments filters are called with. 
I however do not seem to able to have the job traverse more than one filter. Is 
it possible at all, to setup such a chain of filters. Ie have multiple filters 
react on the same mime-type? 
Regards, 
Peter