MAPiEx - Extended Mapi Wrapper C# Help - Attachments?

I'm trying to expose the attachment functionality in my c# code from MapiEx.dll using DllImport:

[DllImport("MAPIEx.dll", CharSet = ExtMAPIProfileWrapper.DefaultCharSet)]
protected static extern void MessageSetSenderName(IntPtr pMessage, string strSenderName);

[DllImport("MAPIEx.dll", CharSet = ExtMAPIProfileWrapper.DefaultCharSet)]
protected static extern void MessageSetSenderEmail(IntPtr pMessage, string strSenderEmail);

[DllImport("MAPIEx.dll", CharSet = ExtMAPIProfileWrapper.DefaultCharSet)]
protected static extern void MessageSetBody(IntPtr pMessage, String strBody);

[DllImport("MAPIEx.dll", CharSet  = ExtMAPIProfileWrapper.DefaultCharSet)]
protected static extern void MessageSetRTF(IntPtr pMessage, String strRTF);

[DllImport("MAPIEx.dll", CharSet = ExtMAPIProfileWrapper.DefaultCharSet)]
protected stati开发者_开发问答c extern void MessageSetHTML(IntPtr pMessage, String strRTF);

But I can't find the correct corresponding item to expose something to set an attachment.

Would

[DllImport("MAPIEx.dll", CharSet = ExtMAPIProfileWrapper.DefaultCharSet)]
 protected static extern void MessageSetAttachment(IntPtr pMessage, String strFileName);

work?

I think it's MessageAddAttachment.