Cool, Scott! I've always wanted to have such a sheet. Congratulations.
How's it working for you?
Seriously, you gotta ask a question, man. As it is, you don't need to post
this on the Excel Programming forum; the solution is just to have your user
place the selection where he wants the new rows to go, then highlight as many
cells (in the downward direction) as he wants to insert - if he wants to
insert three rows, he specifies that by hitting <Shift-Down-Down>, thus
highlighting three cells. Then he can hit <Alt-I>nsert, Rows (I think that's
right, though I'm doing it by memory) and voila! three new rows inserted,
without your even having to write a program for it.
But you wouldn't have posted here if you were satisfied with that solution,
so obviously you have some constraints. What are they? What DON'T you want
your user to have to do, and what are you willing to do yourself, and what do
you want the solution to look like to the user, and what have you tried
already, and what happens when you try that? Give us something to go on.