Beside your spreadsheet cells, have a synchronized listing of the content of the cells.

Any programmer will tell you code listings are MUCH better for getting an overview than having to manually click every cell (including the thousands you think have no content). Quickly typing some numbers in a grid also can be quite powerful however. Why not do both, synchronized? You click a cell and the listing is scrolled to the first mention of it, or creates the first mention.

Cells only provide a view, in which you can select cells. Code and data is not limited to it, which allows other code and data structures. แก้ไข้ใหม่