How do you sum values in a coloumn when it contains #N/A in a ran.
 

I have a range of cells that utilizes the VLOOKUP command to search for
numerical data by descrition and place it in a cell. Then I want to add the
numerical data with the sum function. But in some cells there is #N/A because
the numerical data isn't present. The Sum function always returns #N/A when
this occurs.

Can anyone help with this?