If you have existing data using the Namdhinggo SIL L font and wish to convert your data to Unicode you may use the TECkit mapping file (called "Limbu") that is available from this webpage. Since Namdhinggo SIL L used an encoding that is common among other fonts for the script it is possible that this mapping file will work for texts using those custom-encoded Limbu fonts.

Also provided is the "DevUni-LimUni12" mapping file. It gives the ability to convert between Devanagari script and Limbu script.