sorry i was not precise.
The two files are huge, over 2 million records each. But the format is the same. Only difference is that one file has the additional "1-0-" or "1-1-" or "1-3-".

Im doing it a long way by cutting characters 1-4 off and then using paste and join again later.

Appreciate if you could let me know how to do it using awk. Thanks !!

sara