I wouldn't be too optimistic neither
From what I've seen on the net, e.g. :http://my.afterdawn.com/engage16/blog_entry.cfm/3718/
Your presario cq50z-100 is probably currently running an AMD Athlon X2 QL 60 CPU.
We find that this CPU uses Socket S1G2, where as the mobile Phenom II uses Socket S1G4.
I don't know the difference between S1G2 and S1G4, but usually processors with different sockets are not compatible.
Socket S1 is completely different from Socket AM3 and the CPUs are in no way, shape, or form compatible.
The "g" after Socket S1 denotes an electrical revision to the socket, but the socket is physically the same. For the AMD mobile chips, the revision must be exactly the same for the chip to work- an S1g4 CPU will not work in an S1g3 motherboard. Desktop and server are a little different as there is more backwards compatibility. A Socket AM2r2 Phenom or Phenom II can work in a Socket AM2 motherboard, and so can a Socket AM3 CPU, even though AM3 is a physically different socket.