Hi Mike,
My approach: prior to the calculations, create a two dimensional empty table:
results = Table[Table[{}, columns], rows];
then after filling it with data, export it to a file name ending in .csv
Export[somePath <> "myresults.csv", results];
If you want a header row in your file:
resultsHeader = {col1label, ... };
Export[somePath <> "myresults.csv", Join[{resultsHeader}, results]];