1 Web dispatcher and 2 Message servers

Hi,

I am new to administration and designing part.Pls help me with the following asap ..

We have a EP cluster under a web dispatcher.

We need to install a seperate cluster of WAS for web dynpro alone.( so this will have its own messgae server and db as a cental instance)

Is it possible to load balance these web dynpro servers under the same sap web dispatcher as used for portal given it is a central instace with a DB and own message server...

What are the alternatives ?

Many Thanks for the help,

Ashok