i'm trying to wrap a RAS library, and i've found pretty solid examples
for most RAS API calls...except for RasGetErrorString.  i've seen a C#
example, but can't seem to get the right declaration and use in VB.NET.
the current attempt is:
---
   Private Declare Auto Function RasGetErrorString Lib "rasapi32.dll"
( _
       ByVal ErrorValue As Integer, _
       ByRef ErrorString As String, _
       ByVal BufferSize As Integer _
       ) As Integer

'And then in a button click somewhere...
       Dim errstr As String
       Dim err As Integer = 639
       Dim lbuff As Integer = 256

       Debug.WriteLine(RasGetErrorString(err, errstr, lbuff))
       Debug.WriteLine(errstr)
---

the call to RasGetErrorString fails with an unhandled
System.ExecutionEngineException - even if i trap it in a Try...Catch
block (?).  any help would be appreciated...