Hello! I have a small problem. I have two columns, A and B. In these columns there are returns for different bonds. In column C I calculate the diffence between A and B (C1=A1-B1). In column D I want to calculate the standard deviation of the difference dating 30 data points back. Thus, in D31 i write =STDAV(C1:C30).

This all works fine. However I want to skip having the C column and make the calculations for the standard deviation of the dífference dierctly from the values in A and B. However I have not managed to do so. Please help me out! I know it does not sound worthwhile but having the extra column really messes up my spreadsheet! Any help appreciated! Thanks alot!