Refresh a cell that contains a formula
 

I was given a spreadsheet with 2 worksheets. One worksheet contains the data
and the other is an interface called Quick Search. On the Quick Search sheet
there is a combo box pulling informormation from a column in the second
sheet. When the selection in the combo box changes it updates a
corresponding number in a hidden cell Q2. In another cell R11 a VLOOPKUP
formula exists to pull information and place it in another cell to view the
data.

What I need is when this combo box changes or the cell Q2 is updated with
the corresponding number, the VLOOKUP formula does not refresh it's data in
it's display fields. How can I best accomplish this?