Copy & Paste from one Access field to another

I have a small VB6 app that utilized Access 2000 as the database. In the db I have a field of Keywords, which I have linked to a drop-down combobox. The keywords are sorted by the combobox. The user may also add new keywords.

To insure consistency in terminology, I want the user to be able to copy a keyword from the dropdown list, and insert in another field, which will greatly reduce the problem of spelling errors and non-standard terminology. This second field will be searchable, and will describe items of medico-legal interest

I have tried several methods, but none seem to work. Any suggestions or code snippets?