help with c++ question?

i have a structure like this: enter code here`struct product {

float productID; char productName[24]; float amount; float unitPrice; };

I need to assign the prod[i].productName as prod[i + 1].productName (the value of i doesnt really matter, i determine it using some other function). But I only can assign values to a array of chars with a for loop one by one. The problem here is that i need an index k for the for loop to iterate each character that is being changed as well as an index i to point out which product name im changing. but how do i use two indexes in this datatype wich normally has only one index?