My first effort:

$_='penflillggplmhlllpkolhmhgiokmpmhkegopckdlmlckemhge';
tr/g-p/0-9/;my@x=map{-84+hex$_}$_=~/[A-F0-9]{2}/gi;my@y=
shift@x;push@y,$_+$y[-1]for@x;print join'',map{chr$_}@y;
[download]

“...an ill-favoured thing, sir, but mine own.” —As You Like It (Act 5, Scene 4)

Regards,