ms office excel 2007 cell selection issues

hello.

when you click on a cell, and then hold shift and click on some other cell,
it will select a "path" of cells from the first to the last. the first cell
(i will call this the "primary cell") is special in that if you hold shift
down again, and click on another cell, it will change the path of selected
cells as well as the last selected cell. however, when you move the entire
group of selected cells, excel will change the *relative* location of the
primary cell. how to prevent this from happening?

also, suppose your spreadsheet, for some reason, has 20000 rows, and the
bottom 19000 rows are empty. how can you configure excel so that the
spreadsheet only has 1000 rows (i.e. if you scroll to the "bottom", the row
number is about 1000)?

thanks!