Quote from Eloraam's EAQ's:
“Make cover plates work on X other mod”.
It’s impossible. It’s not a matter of adding cover plates to another block type, but making a block type work inside cover plates. Covers require a huge amount of code, including a lot of custom rendering, and any blocks that use them have to be written, from the ground up, to make use of them. Anything using them would require RedPower Core to function, even if it was possible. So just use the RedPower equivalents.