Creating unique item codes on a running file

Hi Everyone!

I need help on a workflow. I have a running file of inventory and I want to assign unique codes to them every time I add a new item on my master list

e.g.

Item - Code

Chair - CH0001

Chair - CH0002

Table - TB0001

Vase - VS0001

Table - TB0002

my problem is this master list is a running excel sheet so ill be appending my list with new items coming every time I run the workflow with new source file. If I want to add lets say more chairs and vases, what node shall I use so that the item code that will be automatically generated is subsequent to the existing ones

thank you all in advance!