ledger?

I want build a deck that extends from a covered cement patio. The patio is a 4" slab on a cinder block foundation. The slab overhangs beyond the cinderblock about 3". A second story sun room is supported by metal posts which sit on the slab directly above the cinderblock foundation, so it is bearing a load. How do a I attach a ledger board to this? All I can think to do is to pack out the over hang with two 2xs attatched to the cinderblock(but what is an accentable anchor to use into cinderblock) and then attatch my ledger onto that with room for a few anchors on the few inches of the ledger into the end of the slab? All of the existing construction has been done within the past few years and appears to be in very good shape. Any ideas?