When you create a dropdown control you can manually set the DisplayValue|Stored Value.
When I try to populate using xbasic it does not seem to work.

e.control.sendto = "John|[email protected],Dave|[email protected]"
e.control.sendto = comma_to_crlf(e.control.sendto)

Using this method will show the entire string rather then just the first name
John|[email protected]

Let me know if anyone knows how to fix this.