AS Path Filter list

[Anibe Onuche]

Hello All.

I work with an IX and considering implementing bird as my route server.
Was successful in my lab implementation
need a few config to be through.


I want to configure a function on my bird that will only allow certain  
network containing some as-path to be used.(i.e as-path filters)
While at that, other network have valid bgp paths attached to their 
as-path should also be imported.

How do i go about this ?

Regards
Anibe