As far as I've been able to ascertain you can't use LAMBDAs like VBA to perform interactions or manipulations of things outside the scope of the grid. I'd be thrilled to be shown that I'm incorrect, however.
Maybe MS will build in a way to do that eventually? You can't open a door that doesn't exist, though. Being Turing-complete just means we should be able to calculate pretty much anything that can be calculated within reason.