Assuming the employee name, and the job description are in separate columns, I think you need a lookup.
Where is the job description coming from? You have somewhere a list of numbers, with the corresponding job description beside it?
Depending on whether the data is vertical or horizontal, use either Hlookup or Vlookup.
Try this:
Assuming the list of job numbers and descriptions are vertically listed;
highlight the entire range of job numbers/descriptions, and click 'insert/name/define' and call it something memorable such as 'jobnumbers'
Just to test, put a jobnumber in cell a1. in cell a2, put the following formula: =VLOOKUP(a1,jobnumbers,2).
This will find the jobnumber from the range you just named, and look in column 2 of the range to pick up the text.
If the data is horizontal, use hlookup instead of vlookup.
I guess you can work out how to apply that to the actual cells you're working on.
Make sure the jobnumbers are sorted ascending - if they're mixed up you'll get the wrong results. I'm suggesting you use a range, because then you don't have to worry about copying formulas around - it will always refer to that block of cells, and doesn't care which worksheet it's on.
Hope that's what you're looking for.