feed mutiple files from a master source

I have a masterfile (Ecompiled) and would like to feed data from it into two or three other files. (For the purpose of this lets just say the two other files are "Items" & "Customer" ). I have attached a simpler sample of my files. I know there must be a way to do this with vba but i dont know too much about vba and I am hoping someone out there would be able to help. Thanks in advance of your help