Craig,

Unfortunately it's not quite that simple!

The NET equivalent of the StdPicture class (System.Drawing.Bitmap,
System.Drawing.Icon) are not directly compatible - you need to do the
conversion yourself using the OleCreatePictureIndirect API.

I created the following code to create and return a StdPicture containing a
bitmap; you should be able to adapt it to your needs.

<StructLayout(LayoutKind.Explicit)> _
Private Structure PICTDESC
     ' Methods
Public Sub New(ByVal hBitmap As IntPtr) : Me.New(hBitmap, IntPtr.Zero)
End Sub

Public Sub New(ByVal type As PICTYPE, ByVal handle As IntPtr) : Me.New(type,
handle, IntPtr.Zero, 0, 0)
End Sub

Public Sub New(ByVal hMetafile As IntPtr, ByVal x As Integer, ByVal y As
Integer) : Me.New(PICTYPE.PICTYPE_METAFILE, hMetafile, IntPtr.Zero, x, y)
End Sub

Private Sub New(ByVal type As PICTYPE, ByVal h1 As IntPtr, ByVal h2 As
IntPtr, ByVal x As Integer, ByVal y As Integer)
     Me.cbSizeOfStruct = 0
     Me.picType = type
     Me.hBitmap = IntPtr.Zero
     Me.hEnhMetaFile = IntPtr.Zero
     Me.hIcon = IntPtr.Zero
     Me.hMetafile = IntPtr.Zero
     Me.hPalette = IntPtr.Zero
     Me.xExt = 0
     Me.yExt = 0
     Me.cbSizeOfStruct = Marshal.SizeOf(Me)
     Select Case type
           Case PICTYPE.PICTYPE_BITMAP
                 Me.hBitmap = h1
                 Me.hPalette = h2
                 Return
           Case PICTYPE.PICTYPE_METAFILE
                 Me.hMetafile = h1
                 Me.xExt = x
                 Me.yExt = y
                 Return
           Case PICTYPE.PICTYPE_ICON
                 Me.hIcon = h1
                 Return
           Case PICTYPE.PICTYPE_ENHMETAFILE
                 Me.hEnhMetaFile = h1
                 Return
     End Select
     Throw New NotSupportedException(String.Format("picType '{0}' is not
supported", Me.picType.ToString))
End Sub

     ' Fields
     <MarshalAs(UnmanagedType.U4), FieldOffset(0)> _
     Public cbSizeOfStruct As Integer
     <FieldOffset(8)> _
     Public hBitmap As IntPtr
     <FieldOffset(8)> _
     Public hEnhMetaFile As IntPtr
     <FieldOffset(8)> _
     Public hIcon As IntPtr
     <FieldOffset(8)> _
     Public hMetafile As IntPtr
     <FieldOffset(12)> _
     Public hPalette As IntPtr
     <MarshalAs(UnmanagedType.U4), FieldOffset(4)> _
     Public picType As PICTYPE
     <FieldOffset(12)> _
     Public xExt As Integer
     <FieldOffset(16)> _
     Public yExt As Integer
End Structure

Private Enum PICTYPE
     ' Fields
     PICTYPE_BITMAP = 1
     PICTYPE_ENHMETAFILE = 4
     PICTYPE_ICON = 3
     PICTYPE_METAFILE = 2
     PICTYPE_NONE = 0
     PICTYPE_UNINITIALIZED = -1
End Enum

<DllImport("OLEPRO32.DLL", PreserveSig:=False)> _
Private Shared Function OleCreatePictureIndirect(<In> ByRef pPictDesc As
PICTDESC, <In> ByRef riid As Guid, ByVal fOwn As Boolean) As
<MarshalAs(UnmanagedType.IUnknown)> Object
End Function

'*** Example code

           Dim pictdesc1 As PICTDESC
           Dim bitmap1 As Bitmap = Me.SignatureImage
           If (bitmap1 Is Nothing) Then
                 Return Nothing
           End If

           Dim ptr1 As IntPtr = bitmap1.GetHbitmap
           pictdesc1 = New PICTDESC(ptr1)
           Dim type1 As Type = GetType(IPictureDisp)
           Dim guid1 As Guid = type1.GUID
           Return DirectCast(Signature.OleCreatePictureIndirect(pictdesc1,
guid1, True),IPictureDisp)

Hope this helps,

Nick Hall