it all depends on what you're trying to do (exactly) and how you've designed your tables. If tblUser has an autonumber id field and Fname and Lname fields (for example) and your combo list retrieves ID and Fname, you likely ought to be writing the ID to a related table, not the name. This means there has to be a field in a related table with the same data type setting so that will accept the bound column (again, usually ID, which must be a Long if it is to be joined to autonumber ID). A query gets whatever that related data is by matching tblUser.UserID to foreign table tblSomeTable.UserID_fk, where fk suffix is often used to identify that there is a primary key (PK) somewhere in a related table.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.