write pf rules for acces concentrator server (pppoe)

[Fratiman Vladut]

I have an pppoe server. How i can write pf rules for this situation, in 
order to specify any interface, ng0, ng1, .....
I see that isn't any possibility to use wildcard in macros, something 
like this:  ng_if="ng*".
Obviously isn't very easy to have an rule for every ng interface.
How can be resolved?