apache load balancing by URL (is it possible)

Hello,
I have a configuration where I need to do some load balancing.
The problem is that the web servers can share a common db, but not
file systems. for that reason, I need to load balance by URL
For example.
www.mydomain.com/aac I want to go to server1
so all URLs a* thru l* go to server1
all URLs m* thru z* go to server2
I hope that makes sense.
I was wondering if I could have one web server that all requests come
to and via apache URL Rewriting Guide, send the appropriate url to the
correct server.
My questions are
1) is this possible what i am thinking?
2) is the performance going to be bad in this architecture?
3) is there a better way to do it?

Thanks
Randy