' Center the form at the mouse.
Private Sub PositionFormOverMouse(ByVal frm As Form, ByVal _
    target_x As Single, ByVal target_y As Single)
    ' Get the current mouse position.
    GetCursorPos pt

    ' Convert into form client area coordinates.
    ScreenToClient frm.hwnd, pt

    ' Convert to twips.
    mouse_x = frm.ScaleX(pt.x, vbPixels, vbTwips)
    mouse_y = frm.ScaleY(pt.y, vbPixels, vbTwips)

    ' Center the form at this position.
    frm.Left = frm.Left + mouse_x - target_x
    frm.Top = frm.Top + mouse_y - target_y
End Sub

Private Sub Form_Click()
    PositionFormOverMouse Me, ScaleWidth / 2, ScaleHeight / _
        2
End Sub