Answer
This is possible, though it requires being on at least Apps10 UPD8 (UPD9 or later is more reliable) — configure the source lobby element's Web Access URL Address using the syntax lobby/<destination_lobby_id>?pageParams=PARAMETER_IN_DESTINATION_LOBBY:COLUMN_IN_ORIGIN_LOBBY, separating multiple parameter pairs with commas if you need to pass more than one value. For example, lobby/<lobby_id>?pageParams=PROJECT_ID:$[PROJECT_ID]$,FINANCIALLY_RESPONSIBLE:$[NAME] passes the origin lobby's Project ID and Name columns into the destination lobby's Project ID and Financially Responsible parameters respectively.