Please see the official wiki page for the Chainfire Blade. All of your questions will be answered there.
But, if you aren't able to handle the might of such a task, I will provide you will an answer.
The Chainfire Blade is rare, as stated in on the wiki page. AE has 'cracked' down on Shop Loading, so gaining the ID for the shop is completely useless. What I am trying to get at is, you are wanting to 'attempt' to load a rare shop. That will most likely not work as rare shops are usually deleted from the game.
You could always try entering the shop the normal way. The code for the shop is "DoomFire975".
On a side note, before you blatantly post a thread asking a very simple question, try doing some research on your own.
Here is a thread that contains 90% of the Shop/Quest IDs from the game.