Any Way To Easily Add This Computed Column (divide By Zero Problem)

I have this query that I would rather not turn into a stored proc.
because the client really has no budget. I was hoping there would be a
way to add this statement inline to the following sql with some kind of
IF statement without writing it all out. The problem is either total
cost or conversions will have some zeros in the table.

SUM([total cost]/[cost per conversion])

Any help would be appreciated - Happy New Year

SELECT [Search Term], SUM([total cost]/[cost per conversion]) as calcw,
SUM([impressions]) AS impress, SUM([Total Cost]) AS totalcost,
SUM([Total Clicks]) AS totalclicks, SUM(Conversions) AS totalconv,
SUM([Cost Per Conversion]) AS costconv FROM csv where [start date][color=blue]
>='01/01/04' and [end date] <='12/31/04' GROUP BY [Search Term] ORDER[/color]
BY [Search Term] ASC