Reset local administrator password for multiple PCs in Win2003 domain

Hello experts,

I need to reset local administrator password for 500+ PCs using Windows XP in a Windows 2003 domain.

I've the read the post on https://www.experts-exchange.com/questions/21699041/Local-Administrator-Names-and-Passwords.html
but I couldn't figure out the following:
1. I don't know if it will work on Win2003 domain environment
2. I couldn't find the link to cusrmgr.exe file
3. The user who will run the batch script ChngPass.bat is not an administrator on the PC, will he/she be able to modify local administrator password?

Please address all of my 3 issues,

Thanks