Is it possible to extend wifi network with existing coax cable

Greetings,

As I understand it, I can't use another wifi modem on the same cable coming to the house. This would be ideal as I have coax run to where I need it. My wifi is several rooms away and the signal is just no good...tried an extender and it was useless. Would like to make it all happen without drilling into the walls. If there's a solution or a suggestion I would love to hear it!

Thanks for your consideration!