I trust you are using the VB 6.0 Professional or Enterprise edition as you won't be able to communicate with anything using the standard version, at least not easily. You will need MScomm control which is only available in the Professional and Enterprise editions.

I would recommend you purchase Jan Axelson's "THE MICROCONTROLLER IDEA BOOK" it is the definitive text on the 80C52-BASIC chip and has a lot of data on serial communications. Also, she is awesome in her support via Email.

Hope this helps,
Randy A.