irule to read the url and store as cookie

My Existing irule is of the below format. This works fine for the first request when the qwa1234 is passed in the URL. However I need the qwa1234 to be stored as cookie and similarly qwa5678 whenever it is passed in the URI. So please advise how to set cookie for this scenarion. If possible please share the entire irule.

when HTTP_REQUEST { set uri [HTTP::uri] if { ($uri ends_with "qwa1234") } { pool lpqwa1234-25046 } elseif { ($uri ends_with "qwa5678") } { pool lpqwa5678-25046 } default pool app-E2-openhome-25046 }