A sheet contains a list of prices that change weekly - 30 products vertically
each with a column for each weeks price.

Each week a new column is added to the end of the sheet with that week's
price.

Another sheet has a summary of the products and the starting price and
finishing price on a monthly basis.

As the columns with the two prices change inconsistently each month I need
an easy way for an Excel novice to change the column references in the
summary formulas for the starting and finishing prices.

Question: Can a formula contain a column variable which is lookedup from
another cell. E.g. two new reference cells for the starting and finishing
price which contain the two column reference values that all relevant
formulas would automatically update to.

I appreciate any help.