I know there are ways to do this, but I don't know what they are.
I'm curious why you want to set the connections up like this. The router will portion out access to the connection intelligently. Unless all the machines are trying to do downloads or uploads continuously (as in they never, ever stop trying to take bandwidth), you would severely limit each machine's total bandwidth availability by setting up the connections like that.
For example: if your network were set up like that and both of your wireless connections were downloading large files, only half of your total available download bandwidth would be in use, which, in my opinion, is very wasteful.
So, my question is: what is the problem you are trying to solve that causes you to want your network setup like that?