Sierra Wireless MC8780 installation question

Hi guys,
I have a Sierra Wireless MC8780 3G WWAN & GPS PCIe mini-card which I would like to install in a Windows 8.1 laptop. The laptop has a slot to accept the card but I cannot find drivers to suit. Laptop model is Clevo W550SU1. Does anyone know how to get such an installation working?
Thanks a lot!