Connecting networked PC’s to Internet

I have a home network set up through a (netgear)ADSL Modem/router, for the purpose of the router. However I dont want to link to the internet via ADSL but rather via 3G. The 3G internet connection works through the PC it is connected to, but the other PC’s cant access the internet. I have a feeling it has to do with changing the DNS settings on the other PC’s to the PC with the 3G, because that worked before I used the router. If anyone can advise on this and also if I need to change settings in the router ?