I would recommend that you talk to the Dubai Apple Store. They're the only ones who can discuss their policies and procedures, including whether they can accept a credit card issued in another country and whether you can designate someone else to pick up the Mac, with any authority.
Note that buying an Apple device outside of your country can be a risk. Though with a Mac it's unlikely that you would be refused service in Egypt for a Mac sold in another country, that risk remains. I would strongly advise that you just wait until the Mac model you want becomes available in your country.
Regards.