ZHU Controller expressed concern regarding the work around procedure currently required to process flight plan information on aircraft flying into Mexican airspace; noting the procedure diminishes URET's functionality and causes routing confusion.

Narrative

For all flights in my area with destinations to Mexico we are required to put in fictitious points/fixes in order for flight plans to pass to MTY Center. For example we have to put in PNGGG for flights over PNG or LRD..NLD for flights over NLD. These 'required' fixes are not fixes filed by the pilots and are only used to process the flight plans. This is a dangerous work around we deal with daily and needs to be fixed ASAP. Two major problems with this work around are: (1) the processing fix is not even close to the actual fix thus when put into URET the projected flight path is way off diminishing the chance for URET to process possible conflicts as well as the inability to use the route key to see the planes filed path; (2) controllers are spending too much time trying to fix this work around taking time away from separating aircraft by spending time fixing routes. Receiving controllers are having to guess whether or not the aircraft are flying what is shown or flying toward a fix not on their flight plan. This work around is dangerous and I feel needs to be addressed ASAP to avoid any loss of separation due to a computer processing work around.