I agree that this is rather a VBA question or just some kind of a general connectivity issue. If the code hangs because of a broke connection then how do you expect this to be handled on the SAP side?
So your question is not about BAPI but rather how to program in VBA for such scenarios. Try asking on MSDN or whatever it's called these days. Regarding general connectivity check with Help Desk / SAP Basis admin.
As a side note - it's rather unusual for the productive SAP systems to be down for an extended period (other than scheduled maintenance, which is seldom).