The first step in something like this is to confirm the Geodetic Datum for the coordinates.  If these points are in the UAE that would be the Trucial Coast 1948 datum.  http://georepository.com/datum/browse/id/6303

If you now want to convert these to Lat-Long geographic values you'll need to find a converter.  Unfortunately the CORPSCON converter we use in the USA won't work... so you'll have to find something else.  One place might be here:

http://georepository.com/crs_30339/TC-1948-UTM-zone-39N.html

but if not you'll need to keep looking.

Another suggestion would be for you to find and talk to a local surveyor.  They will certainly be able to point you in the right direction if the ideas above don't work.

Good luck!
Dave.

Your coordinates are in a global geographic coordinate system called Universal Transversal de Mercator that use the ellipsoid WGS84  that handles any GPS, you can enter your coordinates in AutoCAD as a point X to East, and Y to North, an easy way to change your latitude and longitude coordinates is joining Google Earth, locate the point with the coodinates that you have, go to the options menu and change your UTM coordinates as you want, you track the Log-point and apply for their properties and you will see the coordinates and changed.

I don't know if this is exactly that you want, hope that will help you.