=F12+F20+F28+F36+F44+F52+F68+F76+F84+F92+F100+F108+F116+F124+F132+F140+F156+F164+F172+F180+F188+F196+F204+F220+F228+F236+F244+F252+F260+F268+F276+F284+F300+F308+F316+F332+F340+F348+F356+F364+F372+F380+F388+F396+F404+F412+F420

i am using this to calculate totals from a set group of colums.. as you can tell they are 8 apart..