Adjusting a formula to return Blank instead of a zero

hai folks,

I am using Macros to "delete a column and insert a new column by copying the same formulas(sum) and number formats".While doing this, the formula is calculating the sum of blank cells and returning zero(which i do not want to display).if i use the spaces instead of zero to display,it is erasing the formula.can u plz help me out with this.

When i used tools->options->view: unchecked the zeros values ...i cannot really enter a zero value for summing,as well the previous cell which contain zero is also removed.