Unless the device has identified the specific 3G modem model as compatible and capable. It will not work. This is one of the ruses (read lies) sold by some EBay dealers. There are known units which have 3G compatibility. It would be better to buy a 3G AP and use that or see if your unit can tether to your Phone. This topic has been asked and answered with a Nope, prior.
I would like to offer you hope. The Huawei is the model with the most potential. But I doubt you will be pleased