The COLUMN function in Excel is a worksheet function that returns the column number of a cell reference. It takes a cell reference as its argument and returns the column number of that cell.

Syntax
=COLUMN([reference])

[reference] - reference for which you want to return the column number.

Here are a few examples of using the COLUMN function:

1. =COLUMN(A1) - returns the column number of cell A1.
2. =COLUMN() - returns the column number of the cell in which the formula is used.
3. =COLUMN(C5:D10) - returns the starting column number of the range C5:D10.