Hello

I like to have an unique validation rule for a columen which contains
id's. I used a therefore simple rule with the build in function
"COUNTIF"
http://www.cpearson.com/excel/NoDupEntry.htm

i.e. "=COUNTIF(E:E;E2)=1"

My id's have the format "n.nn" i.e. "1.1", "1.2", "1.3" etc. and the
cell format is set to "text". The above rule works fine as long as I
have the following id's

"5.1"
"5.10"
"5.100"

The problem which I have now is that EXCEL seems to convert the value
before the COUNTIF is getting applied. It seems that it converst the
value into a number and this results not any more into an unique id.
So any idea's how I can suppress this automatic conversion? To chnage
the id format is not applciable because it is already used.

Many thanks for any suggestions.

regards
Mark Egloff