my $str =
    q[\\\\Srvbuild\e\ADW61\VENDOR\MICROSOFT\PLATFORMSDK\INCLUDE];
my($network, $path) = $str =~ m<^ ( (?:\\+ \w+){2} )(.*)>x;
print "network - $network", $/, "path - $path", $/;

__output__

network - \\Srvbuild\e
path - \ADW61\VENDOR\MICROSOFT\PLATFORMSDK\INCLUDE