THE NEW VERSION 4.40 ALLOWS FOR ALPHA NUMERIC SYSTEM(AS PER THE MANUAL AND RELEASE NOTE)
BUT I AM NOT ABLE TO ENTER.HOW CAN I SOLVE THIS PROBLEM

Double-click the "Name" checkbox next to the node number fields, and you can assign character names to the nodes on a From and To basis (up to 10 characters). These names will show up in place of the numbers on the plots and the reports.