英文版的是否更清楚呢?
Environment variable substitution has been enhanced as follows:
%PATH:str1=str2%
would expand the PATH environment variable, substituting each occurrence
of "str1" in the expanded result with "str2". "str2" can be the empty
string to effectively delete all occurrences of "str1" from the expanded
output. "str1" can begin with an asterisk, in which case it will match
everything from the beginning of the expanded output to the first
occurrence of the remaining portion of str1.
就是把等号左边的字符串替换为等号右边的字符串,现在清楚不?