I have a client with about 10 000 extensions. They use extension mobility. I need to change all 10 000 extensions from 5-digit to 6-digits. Also, I would need to change the End User telephone number to reflect the new 6-digit range. Looking at the BAT tool I do not see an easy way around this, I would need to export all details for the EM from the CUCM into the BAT then make the changes, then upload, I see many problems with this. Surely there must be a quicker and safer way.
In addition to the good tips from Ven & Java (+5 each) you may want to look at this blog from Bill Bell the UCGUERRILLA;