CJ seems to know what you're asking, but I don't get it. If his post works for you then feel free to ignore this question, but what (more exactly) are you trying to do?

The way I picture it, you're in Outlook's calendar, looking at an appointment and editing that appointment's notes, the body I mean. Now you want to <Alt-Tab> to Excel, point to a particular cell that had a date field in it, and click a button ... somewhere ... that causes the date in Excel to be pasted into the appointment notes?

That doesn't really make sense when you can just <Ctrl-Ins> and <Shift-Ins>, so I'm thinking you meant something more complicated. But what?