I don't know what the Escort uses for a fuel filter, but Foci don't use anything all that special. It's just a simple, generic external filter that's sold at any parts stores or even Walmart. See if yours looks the same, and if so, throw it on.
Should work as long as the lines connect properly since these aren't complicated filters like found on other cars as mentioned above. If Ford changed clip designs when the Focus came out, the Escort unit won't work.