When running script via VMware tools when power changed, some script commands(such as copy) failed.

I came across a very strange question. I tried to create some custom vmware tools scripts, such as a new bat file. This file contains a lot of commands, mostly copy command such as "copy file://\\192.168.172.5\abc.exe c:\". I set this file as custom script for Script Event--Power on guest Operating System. Everything goes well with the bat file when I tested it. But after I change the power state to Power on, all other commands work fine except the copy commands in the bat file. Why? How can I make them work? Off course not the network problem. And this makes me very confused.