Irule redirect that sits behind a proxy

For all the Irule experts, can you help me out with this!

I have a Application that sits behind a proxy server --user does not want to move the app from the proxy due to DNS changes which is not happening. So I need a rule to insert into the proxy that redirects to a site page from requested 302 redirect but, need that direct to call up pool b. Currently calling up pool a only. Note: On the VS, there are no irules assigned as the irule is held in the proxy which is this:

elseif { ($requestURI starts_with "/help/ui")} { pool pool b

Works great like this, but not what they want---need the redirect.

example of what I need:

elseif { ($requestURI starts_with "/help/ui")} { http::respond 302 location "; pool a tcp close

} elseif {($requestURI equals "/")} {

 pool pool b

} }

Thanks