Passing Parameters(authenticated on AD) to web server.

i think some more info is needed.

you using APM module? you want APM to pick up that request and then send them to AD for check and afterwards pass them on to be backend server?

have you already built an APM profile / policy, how does it look?

if the above is kinda correct then you could look at clientless mode.

https://devcentral.f5.com/questions/apm-clientless-mode

in that case you have to write the irule logic to pickup the username and password from the URI, feed that into the session username / password fields and get going.