If all the numbers in your column have the same number of digits, use Format
Cell, on the Number tab select Custom and (based on a number with a maximum
length of 10 digits) enter 00##########. This will force the leading two 0's
to remain for any number up to 10 digits.

Alternately, you can format your colum as Text before entering numbers.

"klieske" wrote:

I have a long spreadsheet for my inventory in a library and for some reason
the 2 zero's will not stay after i put in a number. Such as: 0033995753.
The zero's get dropped and I cannot figure out how to get them back. I am
using Office Pro 2003. Thank you!