Without access to the old site, or control of the DNS for the old sites name there is no forwarding that can be done from the old site to the new one.
If you have access to edit the old site (which would be exceedingly odd if you don't have access to add a redirect in the control panel) you can replace the old sites page with just a simple redirect statement. But again, If you don't have access to that site then there's nothing that can be done to redirect isowall.ca to isowallrockwall.com.