I think you mean "H:mm |", anyway that wouldn't matter.
then Nick would be made like this:
StampFormat = "H:mm |";
aStampFormat = StampFormat.split(" "); //array: H:mm,|
StampLength = StampFormat.split(" ").length; //value: 2
StampedNick = "11:59 | <insert nick here>";
aStampedNick = StampedNick.split(" "); //array: 11:59,|,<insert,nick,here>
aNick = aStampedNick.slice(StampLength); //remove the timestamp (in this case 2 space-separated character blocks, since StampLength = 2)
Nick = aNick.join(" "); //put the nickname back together in a string.
put all these steps together and you get
var Nick = StampedNick.split(" ").slice(StampFormat.split(" ").length).join(" ");
I hope that makes it clear