I don't understood your "ipconfig bla1", but suposese a simple argument...

open(STATUS, "ipconfig /all |");
while (<STATUS>) {
     print $_  if ( /Physical/ );
}
close(STATUS);
__END__
    Physical. . . . : xx-xx-xx ...
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If only needs to execute ipconfig with parameters its correct. If need other interacts maybe needs try other open forms.