Upgrading old program?

We have the source to an existing DOS program that we think uses CodeBase.
Our evidence for that assumption is the presence of D4DATA.H (12/9/1999 @[EMAIL PROTECTED]
).

  1. Can someone tell us what version that might be?

  2. Assuming we write a new version in VB, can the new CodeBase read the
old data?  If not, is there a utility to convert the database?

Thanks.

Dick.