Is there such plug-in which can boost the name length?

I'm not sure if it can boost your name length... I didn't say anything... but stuffplug can make multiple line nicknames....
You could look for some patches and things and they might be able to.

Before you jump down everyone's throat about this try taking into consideration that the length that is set is a given by the Messenger Protcol. Which means it has to be less then or equal to the max length or else it will not work. This is something Microsoft has set it is not something a programmer can change.

Now I think you owe qgrossel an appology for being so rude. He gave you ideas that you can try.

In other words it cannot be done.