HAProxy or APACHE2 Loadbalancing on URLs

HAProxy or APACHE2 Loadbalancing on URLs

I want a Loadbalancing on URLs (with GET parameters), so i need a URL
Mapping, instaed of using only hosts (ip-adresses).
For example, this apache2 configuration:
BalancerMember "http://server.domain:8080/server/process?workerName=Worker1"
BalancerMember "http://server.domain:8080/server/process?workerName=Worker2"
Proxypass /entry balancer://workers
... do not work, cause Apache will add an / at the end of the URL, so the
passed request will result into 404
"server.domain:8080/server/process?workerName=Worker1/"
And HAProxy dont work too, cause i cant find any options or parameters to
do that. The server option allow only a hostname or ip-adress. A redirect
with "redir" is also no solution.
Any one can help or have an idea?