excel automation c#

I am trying to create excel order form which will have price and qty columns and customer will put the values in the qty column and excel will update order cost column. problem i am facing right now is that number of columns in excel file is changing i.e. u开发者_如何学Goser can select multiple columns. so price column location is different every time how to put formula in the column in order cost column to reference product price column

If your qty column has a fixed column title, you could find it out by iterating the first row, and than use that information to correctly position the order cost formula.

But, it's hard to give a useful answer if you don't provide any more info, example of your tables or code...