Here is an example map_0r file for Arabic/Urdu support. Note that the name of the map makes use of the mnemonic letter used in the file name, so the example map names would be modified depending on the name of the mapping file.
Between the #BEGINMAP and #ENDMAP lines are lines defining the translation.
The first hexadecimal number indicates the code being mapped from, and the second value indicates the code point being mapped to. The internal transitional form requires two hexadecimal digits, and the Unicode form requires four hexadecimal digits. Internal transitional form must always map the bytes 0xXY as 0x00XY for values from 0x00 through 0x7F, except for the error character 0x1A that maps to Unicode 0xFFFD.