Must all cells in a column be the same width?

Can I programmatically set a cell width to be different from other cells in a column? I do not want to merge two adjacent cells.

No, there is only one width per column. The only way to have the appearance of different column withds on different rows is to use covered cells. If teh adjacent cell is empty, you can have ''long'' text float over an empty adjacent cell using using FloatingCells which might give the appearance of a cell being a ''double wide'' cell. This only works for empty adjacent cells.