Hi Matthew,
You can't change the size of an individual cell.
You can change the width of column(s) or
the height of row(s)
- to a specific width
- to autofit a selection.
Column selection(s):
Format, Column, width, specify width or autofit a selection
Row Selection(s)
Format, Row, width, specify height or autofit a selection
You can double click on the border between two column headers
or between two row headers to fit row or column to selection.
If you want a programming solution record a macro to at least
get a start.