Each cell in my worksheet is a function call that is requesting data from
webservice. But at times some of these cells dont have any values; and this
is not an error on the part of the webservice but it happens so as thre is no
data for that particular function call.

Now when I am using a subtraction or and addition or using any factor to
divide this number in a different cell I get a #VALUE error. I know I can use
the "IF" function to get over this error but if there is any other way around
this I would like to know. Also if there is a cell format that will change
the null cell to a Zero (0) with a different color will do (color change will
make me aware that it is something that the formating has done and the actual
cell value is not a Zero.)

I am using Excel 2003 Professional