Merging two account database

Good Morning.This is a tough one which i encounted this weekened.Two offices which are using the same Lacert tax software.Decision made to move into one office.What we need to do is cosolidate the other offices accounts & data and merge it into the current Lacert app.Any Help or thought in how i can accomplish this.The program has an export utility,I exported two files to test but it does not have an import utility,Thanx Aziz