vb.net try..catch..retry question

In VB.NET I have a class that allow the selection of a drive, if that drive is not available i.e. ‘A:\’ then an exception is raised in a Try..Catch Error handler. This handler generates a standard Windows message box with Retry, Ok and Cancel options. If the Retry option is selected how do I get the program to exit the Error handler and re-enter the function to see if the drive is now available and re-raise the exception if necessary?