=SUM((C12*D$7)+(G12*H$7)+(K12*L$7)+(O12*P$7)+(S12*T$7)) is my current formula. However, there's the chance that at least one of the columns C, G, K, O or S might be hidden. Without first making sure that there's absolutely no data in any of those cells (because this is being coded for widespread use throughout my company and not everyone is up to speed on sensibilities), how can I change that formula so that it will NOT include any hidden values?
I'm using Excel 2002 (or 2003, I honestly can't remember what we have at work).
Hilariously, there's a Microsoft support site that attempts to answer this question but not only do they admit that there's no easy way to do it, their formula doesn't work for me.