ACL '-f' option not working

I tried to use 'ACL -f' to upload the pattern from a file but cannot make it work.  I configured it as below,  frontend PUBLIC        bind :80        acl rec_w7 path_beg -f test.cfg        use_backend WAS7-BACKEND if rec_w7 .. Here test.cfg is a file containing one pattern as below,  /abc/

content based routing with rewrite (reqrep)

So I'm trying to come up with the best way of doing this, but am having a heck of a time. Basically I have several different backend service pools, and I have one externally facing haproxy router. I want to take a map of public URLs and route them to specific backend URLs. For example