Hi Curly.
You will get more expedient responses by posting to the *Excel* newsgroup.

I did find the following in the Excel help file which indicates number
precision is 15 digits, so doesn't look like you'll be able to see more than
15 digits.  You might see more accuracy if you use the scientific notation
though.  Go to Format>Cells and select Scientific.

Feature Maximum limit
Number precision 15 digits
Largest number allowed to be typed into a cell 9.99999999999999E+307
Largest allowed positive number 1.79769313486231E+308
Smallest allowed negative number -2.2251E-308
Smallest allowed positive number 2.229E-308
Largest allowed negative number -1E-307
Length of formula contents 1,024 characters
Iterations 32,767
Worksheet arrays Limited by available memory. Also, arrays cannot refer to
entire columns. For example, an array cannot refer to the entire column C:C
or to the range C1:C65536. However, an array can refer to the range C1:D65535
because the range is one row short of the maximum worksheet size and does not
include the entire C or D column.
Selected ranges 2,048
Arguments in a function 30
Nested levels of functions 7
Number of available worksheet functions 329
Earliest date allowed for calculation January 1, 1900 (January 1, 1904, if
1904 date system is used)
Latest date allowed for calculation December 31, 9999
Largest amount of time that can be entered

Good Luck!