Mona Sabry

Your best bet is probably to do this:

1. take a copy of the sdlxliff files in the target language folder and put then in a new folder
   
   
2. with a text editor change the languages to suit.  So search for this:
   target-language="ar-AE"
   replace with this:
   target-language="ar-EG"
   
   
3. Then create a new project using these sdlxliff files
   
   
4. Translate them
   
   
5. When you are finished copy the translated sdlxliff files into a new folder and rename the files (if necessary) so they have the same name as the original ones in 1. above
   
   
6. with a text editor change the languages to suit. So search for this:
   target-language="ar-EG"
   replace with this:
   target-language="ar-AE"
   
   
7. copy these files back into the original project folder and make sure the names of the files are exactly the same as the originals

Now open the project and you should see all the files are translated and you can create your return project package.

There are variants of this approach... you could pre-translate the project in 3. using MyMemory and update to a TM.  Then add that TM to your original project using AnyTM. You could also try adding MyMemory to the original project using AnyTM, but I have not tested this approach... you should though as it might be the easiest solution of all if it works.