How do I send email with attachments??

I am needing to click a button which send some parameters to a function which opens the users default email program and creates a new message.

The code I'm using does this just fine, the only problem is I cannot figure out what the parameter would be in order to attach a file.

Here is what I am using...

VB Code:

Public Function OpenEmail(ByVal EmailAddress As String, _
                              Optional ByVal Subject As String = "", _
                              Optional ByVal Body As String = "", _
                              Optional ByVal Attachment As String = "") As Boolean
 
        Dim bAnswer As Boolean = True
        Dim sParams As String
 
        sParams = EmailAddress
 
        If LCase(Strings.Left(sParams, 7)) <> "mailto:" Then _
            sParams = "mailto:" & sParams
 
        If Subject <> "" Then _
            sParams = sParams & "?subject=" & Subject
 
        If Body <> "" Then
            sParams = sParams & IIf(Subject = "", "?", "&")
            sParams = sParams & "body=" & Body
 
            '****** What is the parameter for attaching a file??
            sParams = sParams & "attachment=" & Attachment
 
        End If
 
        Try
            System.Diagnostics.Process.Start(sParams)
        Catch
            bAnswer = False
        End Try
 
        Return bAnswer
 
    End Function

Could someone please help?!

Thanks
CC