I'm drawing lines, making rectangles for house plans on grid paper I've set
up. It's very tedious trying to get a horizontal line to be exactly
horizontal, sometimes my hand isn't steady enough, or the mouse doesn't have
good enough resolution.

I'd like to have a "snap to" function so that a line I'm drawing will do two
things: first, snap to a perfect horizontal or vertical orientation if
that's what I'm trying for, and second, snap to the nearest grid
intersection for it's starting and ending point.

Is this possible in Excel 2003, and if not, is there a subsequent version
that has this capability?