Binaryworld - CLSIDToProgID - Convert a CLSID into a ProgID ... [ VB -> COM-COM+ ]

Private Declare Function ProgIDFromCLSID Lib "ole32.dll" (pCLSID As Any, _
  lpszProgID As Long) As Long
Private Declare Function CLSIDFromString Lib "ole32.dll" (ByVal lpszProgID As _
  Long, pCLSID As Any) As Long
Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (dest As _
  Any, source As Any, ByVal bytes As Long)

' Convert a string representation of a CLSID, including the
' surrounding brace brackets, into the corresponding ProgID.

Function CLSIDToProgID(ByVal CLSID As String) As String
  Dim pResult As Long, pChar As Long
  Dim char As Integer, length As Long
  ' No need to use a special UDT
  Dim guid(15) As Byte

  ' convert from string to a binary CLSID
  CLSIDFromString StrPtr(CLSID), guid(0)
  ' convert to a string, get pointer to result
  ProgIDFromCLSID guid(0), pResult
  ' return a null string if not found
  If pResult = 0 Then Exit Function

  ' find the terminating null char
  pChar = pResult - 2
  Do
    pChar = pChar + 2
    CopyMemory char, ByVal pChar, 2
  Loop While char
  ' now get the entire string in one operation
  length = pChar - pResult
  ' no need for a temporary string
  CLSIDToProgID = Space$(length \ 2)
  CopyMemory ByVal StrPtr(CLSIDToProgID), ByVal pResult, length
End Function