Is your machine capable of this? For a large tool, there is a setting in the tool table to fix the pocket. This means that tool will only go back in that pocket and you leave the pockets on either side empty. For a heavy tool, this should be set in the pocket table somewhere. But that is dependant on the machine tool builder. On your machine, I do not know. All of this also depends on whether your machine is a fixed pocket machine or a random pocket machine. You should be able to find this in the machine manual., the one that was supplied by the builder, not Heidenhain.
Paul