You could write .NET or VB6 as a front end to the Access app, but you'd have to duplicate all the work.
You could also write VB6/.NET COM .dll's, and have access call them, but it's more work than it's worth.
Access can do amazing things, and small apps can be built very quickly. The problem is not the tool (although file based databases are more apt for corruption, and I've had several forms become corrupted). The problem is the availability of Access on most business user's desktops, and the need to rely on VBA to get things done. Excel macros are also VBA, but you can do alot with Functions.