I'm hereby making this a "No Stupid Questions about AI" topic.
Agentic tasks is one thing I don't much understand as far as the workflow. It makes sense how I could use Copilot to do things within MS applications. I don't understand how an external agent like Claude would interact with MS applications (or other programs) to do any agentic tasks.
You're basically where I was at 3-4 months ago. For me, going from 0 -> 1 was to stop trying to figure out how AI was going to build what I needed. Instead, do this: open Claude, type "How can I use Claude Cowork to create agentic tasks in MS Excel?" That should give you a basic understanding, then you can move on to working on your first specific task / project.
A couple more things:
1) Don't jump straight into Cowork or other tools to try to build automations. Work with the chat tool to build what you want to accomplish, then then ask the chat how to automate what you just built.
2) Don't try to one-shot your prompt by adding in a ton of context up front. Instead, tell it what you want to accomplish and then tell it to ask clarifying questions before executing anything.