MS: Addressing a N/A value in a formula: How?

["rudolf stricker" <rst@xxxxxxxxxxx>]

In my data set of securities, some days are not available, because
these days were holidays. So MS (show holidays selected in the option
section) shows a "N/A" in the data window for these days. 

Because of several reasons, I want to fill these gaps by a formula
e.g. 
	 If(V=0 OR V="N/A",PREV,V)
but, unfortunately, MS seemingly doesn't like this "N/A" in a formula.

My question: 
How can I address these N/A values in a formula?
Or is there a work-around to set "missing values" e.g. to the
preceding values?

Any hint is welcome.

mfg rudolf stricker
|
| Disclaimer: The views of this user are strictly his own.