CardSprint Loyalty SQL database

We currently use our own program which was written in Visual Basic and links entered data to an Access file. Information includes customers’ personal details and transaction values. There are approximately 30 different fields. The program also pulls data from the Access file based on a number of entered variables, so we can extract a list of certain customers. We find the software runs very slowly when the Access file gets large (eg 10,000 customers and 40,000 transactions). ? We want a better solution and I Believe that an SQL database would run more efficiently. If so, we’d need the relevant changes made to link the Visual Basic code to an SQL database. We have the source code.