Excel 2000-

Is there a way to allow different users to see only their rows in a
community spreadsheet based on "their" ID being located in a particular
column.

Simple example: 20 rows in sheet. 5 users have 4 rows each in sheet.
Column A has NT User ID for each user. I want each to see only his rows and
NEVER be able to see the others.

I get the user logon from NT so I know who opened and can use VBA code to
apply a filter. But there are some many ways for a user to Unfilter to see
all rows.

Any ideas? I am currently working on a two sheet solutions copying data
back and forth but it is getting complicated.