Center UserForm in window

I added a button to the ribbon of a new email window that when clicked brings up a UserForm. I would like for the UserForm to open up in the center of the new email window as opposed to right now that it just opens up at random places of my 3 screens. Below is the code that I have so far. Thanks in advance.

Code:

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Sub Add_Client_ID()
Dim wdDoc As Object
Dim oRng As Object
Dim oBM As Object
Dim oFrm As UserForm1
Dim strText As String
    On Error GoTo Err_Handler
    If TypeName(ActiveWindow) = "Inspector" Then
        If ActiveInspector.IsWordMail And ActiveInspector.EditorType = olEditorWord Then
            Set wdDoc = ActiveInspector.WordEditor
            On Error Resume Next
            Set oBM = wdDoc.bookmarks("_MailAutoSig")
            If Not oBM Is Nothing Then
                Set oRng = oBM.Range
                oRng.Start = oRng.Start + 2
                oRng.collapse 1
            Else
                Set oRng = wdDoc.Range
                oRng.collapse 1
            End If
            On Error GoTo Err_Handler
            Set oFrm = New UserForm1
            With oFrm
                .Show
                If .Tag = 0 Then GoTo lbl_Exit
                strText = vbCr & "=================================================================" & " " & vbCr & _
                          "The following information is for HIA/GK internal use and can be ignored." & " " & vbCr & _
                          "File ID:_      " & .TextBox1.Text & vbCr & _
                          "Type_PL:_    " & .ComboBox1.Text & vbCr & _
                          "Type_CL:_    " & .ComboBox2.Text & vbCr & _
                          "Drawer:_    " & .ComboBox3.Text & vbCr & _
                          "POL:_          " & .TextBox2.Text & vbCr & _
                          "================================================================="
                Unload oFrm
            End With
            oRng.Text = strText
            oRng.Start = wdDoc.Range.Start
            oRng.collapse 1
            oRng.Select
        Else
            GoTo Err_Handler
        End If
    Else
        GoTo Err_Handler
    End If
lbl_Exit:
    Set wdDoc = Nothing
    Set oRng = Nothing
    Set oBM = Nothing
    Set oFrm = Nothing
    Exit Sub
Err_Handler:
    Beep
    Resume lbl_Exit
End Sub

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