A wireless expander is to allow you to put wireless detectors onto a wired panel. (as a rule) it will not in itself wirelessly communicate with the panel.
I would suggest a hybrid panel, say a galaxy 2-20 or a scantronic with wired detectors on the one side and wirelss the other. But you may need more stable detectors on the wireless side. If so honeywell do a wireless dualtech for the galaxy range.