Is this you are expecting?
Example.

 my $data=<STDIN>;
        if($data =~ /ipw\.r[^a-p][a-z]*/)
        {
                print "Match\n";
        }
        else
        {
                print "Not Match\n";
        }
[download]

OutPut

ipw.raasdfdsf
Not Match
ipw.raasdfdsf
Not Match
ipw.rgdfgsdfsd
Not Match
ipw.rrwgorga
Match
[download]