Setting names to instances

I have a grid of x by y, and at each (x,y) position I have a node. I have some script that automatically generates the nodes, but they are all called node (clone). Is there a way I could give them each a unique name like node00_00 for the first node, then node01_00 for the second or something similar?

clone.name = String.Format("{0} {1}, {2}", source.name, x, y);

This will generate a name such as "node 2, 63"

clone.name = String.Format("{0}{1:00}_{2:00}", source.name, x, y);

This will generate a name such as "node02_63"

Two different flavors. In my opinion the first is more readable.