Copy field def in code

I have a field that I added to a table. It is just another field CWho1 (in
the same table) with a new name COwner. All other attributes are the same.
I can't figure out how to create a field in code that has "lookup" properties
and was wondering if there is a way to copy the field definition from one
field to another and rename it in code. (It is in a backend that I don't have
access to, thus I need to perform the addition in vb code).

If not, is there a way to set the lookup properties in the field? I know
there are drawbacks to the lookup properties, but what is done is done for
now.

Thanks for the help.
Dave