mask/hide browser url header after redirect.

This get's a little trickier, but you'd generally replace an HTTP::redirect with an HTTP::uri command to transparently alter the URI path on the ingress traffic flow.

HTTP_REQUEST { 
    if { [class match [string tolower [HTTP::uri]] starts_with Mortgage_iRuler] } {
        HTTP::uri [class match -value [string tolower [HTTP::uri]] starts_with Mortgage_iRuler] 
    } 
}

So the client entering /bob would show up on the server as /mortgage/default.aspx?clientid=1021 (you may have to alter your existing data group entries to just reflect a specific URI and not the entire URL). Where it gets tricky is if 1) the URI pattern for a given user changes from that data group entry during the user's session, and 2) if the application responds with document object references (images, css, js, etc.) that use the real URI path.