You may have to find a good substitute....Feta, if you can find it there. Other substitutes could be Parmesan or Romano. It is very difficult to find specialty cheeses there, you can always check at WhyNot and see if they have anything that you might be able to use.
Casablanca Restaurant and Deli on Rizal Boulevard serves up some Mexican selections. Put in a call. Good luck.
Ahhh,OK, it's similar to Feta. 'The Goatary' in Duma makes a nice Goat's milk Feta. They have coolers at Hypermart (near the checkout registers) and at Lee Plaza (next to the diary products / cheeses. They also make a 'Fromage Blanc Mexicaine', but the Feta is maybe closer to what you're looking for.