Whem exporting a list of numbers beginning with zero to an excel
spreadsheet,excel drops the zero.When you format the column
(numbers,text)still no zero. How do you get around this?

Have you tried this:
right-click on the column heading and choose Format Cells
on the Number tab, in the Category section, choose Custom (at the     
                                                                      
       bottom)
in the Type section to the right, enter 000000000 (9 zeros) to force 9
digits in your number (or what ever you need)
click okay and Excel adds leading zeros as needed to make 9 digits

You need to convert to text 'during' the import, not after.

When the import wizard comes up, highlight the column you want to
format with the leading zeros, then choose 'text'.

Understand, however, that this is no longer a number and cannot be
used for mathematical functions.  It will be 'text'.

Tools->Options->View->Zero Values

Make sure the "Zero Values" check box is checked in the
Tools->Options->View dialog box.

The way to approach this depends on the data.

- Data is text that looks like a number to Excel: I get this problem
all the time (text like 1-MAR23 gets converted to a date; bank account
numbers lose leading zeros, etc). Respree is correct, you need to
format the cells as text before you put the data in them. If you're
using cut and paste this is easy (you can also paste the data to see
which columns need to be formatted, format those columns as text, and
then paste the data again - I do this often). If you're exporting
directly to Excel, you need to find a way of exporting to a file
instead; then you can use Excel's text file import wizard and mark
those columns as text.

- Data is numeric but should be displayed with a leading zero or
zeros: Something like canadianhelper's suggestion is the way to go.
Specify the required format. Alternatively, you can format the cells
as text as above (for example if there isn't a single format, but
leading zeros should still be retained). If you want to use the
numeric value you will need to explicitly convert it using the VALUE()
function.

Methinks I misinterpreted the question. Ignore my answer.

it is easy. 

if you want to display 0000 in the excel, you just need to input '0000.

In Excel 2003 (and applicable to earlier versions too, AFAIK) - 

Data->Import External Data->Import Data
(Then select the file containing the data and click on 'Open')
Click on 'Next'->'Next'->
(Select 'Text' from the radio button selection at the top)
Click on 'Finish'

As suggested by respree-ga (with a different description of
essentially the same process), this data is then recognized by Excel
as textual, and cannot be operated on as numerals can.

Canadianhelper is correct.  I assume you want them to be real numbers
so you can perform arithmetic operations on them.

After you export the numbers to Excel highlight the cells you want to
format.  Then:

Format->Cells->Number->Custom

Then type in as many zeros as you want in the custom format and the
data will be stored numerically with leading zeros if the number does
not have that many digits.

Hmmm... I hadn't tried what canadianhelper suggested - didn't realise
that this was what his description meant, actually :)
ansel001 made it clear. Thanks!
I guess that means that if you want to retain the numeric nature of
the data, then that's the way to go!

Here is how to import data with leading Zeros:
~ Go to Data -> import external data -> import data
~ This opens a dialog box where you can browse and choose the text
file from which you can import data
~ Once you choose the text file, you get into the text import wizard
~ Select if you have a fixed width or delimited file and click next
~ In the next step, you can specify the delimiter character (comma, for example)
and click next
*** In the 3rd step, you set the format of the columns that you are
importing. Here is the solution for you. In this box, you will get a
preview of all the columns that get imported. Assuming, that you have
leading zeros in the 2nd column, click over the column. This will
select the column with leading zeros. Now choose "Text" radio button
that you find above the preview frame. It would be "General" by
default. Click on finish
Now click Ok
You can see that the data gets imported with leading zeros.