I picked up a very nice used Corian countertop with intregal lavy sink. The sink has a hole for overflow with a tube fitting facing downward. I assume I can just connect a length of plastic tubing to this fitting, but how do I connect the other end to the drain? Are there pop-ups available that are designed for this? The Pop-up included with the Kohler faucet I want to use won't work, as it's designed for a standard overflow. Any suggestions welcome!