Alex,

There are a few solutions. Two are (might have typos, but you should be
able to get the idea):

select Employee_last_name, Employee_first_name
from tbl_employee
join (
  select '009' as id union all
  select '008' as id union all
  select '007' as id union all
  select '007' as id union all
  select '006' as id
) as IDs
on IDs.id = tbl_employee.employee_id

or to make the specification of ids simpler:

declare @ids varchar(1000)
set @ids = '009008007007006'
declare @idlength int
set @idlength = 3

select Employee_last_name, Employee_first_name
from tbl_employee
join a_permanent_table_of_integers_from_0_to_whatever as Nums
on employee_id = substring(@ids,@idlength*n+1,@idlength)
and n < len(@ids)/@idlength
-- [n] is the column name for the permanent table and should
-- be that tables primary key

-- Steve Kass
-- Drew University
-- http://www.stevekass.com

The easy way is a UNION, based on a guess about the DDL you did bother
to post and the uniquness of emp_id:

SELECT last_name, first_name
 FROM Personnel
WHERE emp_id IN ('009', '008', '007', '006')
UNION
SELECT last_name, first_name
 FROM Personnel
WHERE emp_id = '007'