Have a dsl modem downstairs and need to connect to a computer upstairs. I am not allowed to run an ethernet cable dont want to run wireless router. Any other way 2 do this. Phone jack or power outlet

I don't Think You'll be able to do that without a cable or router
you can get a cable from about 45m for around $30AU.
Another thing is that you could try to move the dsl modem upstairsbut oh well.
i use a router,i got it about $90-$100AU.