Is it possible to auto-fill a column of cells dependent the rows in another column?

Hi All,

I'm in a situation where I have a number of formulas in place that are dependent on data imported from another source. As the row count for the data will be of varying lengths, is it possible for excel to understand what the last row is a value exists on in column C, and from there, automatch the formula to that row in column D to meet the final value in column C? Preferably this would occur when the data in column C is imported

I understand dragging down for say 100 cells in column D should cover the imported data, if, for example, the maximum rows will always be between 70-80. The issue with this is, a 0 value will be returned, which will affect other formulas on my spreadsheet. 0 values for that column can't be set to not showing, as they may show up earlier in the column, which is data I will need to have showing.

Thanks in advance.