Hi Ed

The cmu cells around your windows and doors are probably poured solid with concrete, which is required by the Standard Building Code. Sometimes something may block them from filling up, however that is not very common in newer homes.
Most everyone uses" tapcon" screws/bolts to secure anything to concrete blocks and /or concrete.They are usually blue in color. You have to use the right size masonry drill bit for them to be secure. A vibrating drill will make the drilling much easier.
I am unfamiliar with your panels, and they may have different type of fasteners, which are designed to be left in the block for the next use of the panels.
Good luck with your project, and e-mail me if you have any questions.
Barry VaughtEnterprise@aol.com