How can I change the environment from within my Perl script?

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question: ⭐ (programs and processes)

In WIN NT4.0 or WIN98 workstation, how do we change path?

system("set path=%path%;c:\xx;c:\xx\sss;")
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does not change my path.

Originally posted as a Categorized Question.