The OptQuest Developer Kit handles the same error codes as CB.MacroResult in the Crystal Ball Developer Kit. However, the OptQuest Developer Kit can take action when an error occurs (when a non-0 error code is generated). Error handling statements can take the form of On Error GoTo or On Error Resume Next.
For example, consider the following code sample from OptDevKitRuntimeSample.xls:
On Error GoTo ErrorHandling
This means that when an error condition occurs, the ErrorHandling code is called. Then, ShowError is called, and a series of messages describe the detected error. For details, look at the code in OptDevKitRuntimeSample.xls and search for ShowError. Also, look up CB.MacroResult and CB.MacroResultDetail in the Crystal Ball Developer Kit User Manual.