Not using forms or reports or data views here is what I need to do.

Lookup a value in a table based on two existing values of a record in the record to be updated.

Something like this:

Field1 - Field2 - Field3

Field1 is the result of a lookup based on Field2 and Field3. Can be Dlookup or SQL. User selects values for Field1 and Field2 and the result of the lookup is posted to Field1

I have not been able to figure out how to embed this in the definition of the table.