sprint mifi 3g/4g internet with airport express?

So I have a sprint mifi 3g/4g card from novatel wireless (mifi 4082). It works well on the road, but I would like to use my airport router at home because it has better connectivity and allows more users. How to do I use the mifi in conjunction with the airport express so that i have the sprint 4g internet via the apple airport express without having to log onto two different wifi networks?

I have tried plugging the USB cable from the mifi to the USB port on the airport, but it does not work.

Being able to do this would effectively eliminate the need for a separate ISP for home and mobile internet. Plug the mifi into the airport when home, and just take it with you on the road. Any help would be greatly appreciated and rewarded.😀