Converting DAO to ADO is not necessarily a one-to-one conversion. Unless you really want to convert the DAO to ADO, you don't need to do it to convert the db to A2K. To continue to use the DAO code, you'll need to find all the DAO objects and qualify them so Access can interpret them correctly. So Dim MyDB as Database becomes Dim MyDB as DAO.Database. As Table becomes As DAO.Table, As QueryDef becomes As DAO.QueryDef, etc.
Then make sure that the DAO 3.6 or 4.0 library is present in the references list. To look at the references, open any code module and select Tools/References from the menu.