Saving changes to Column Format in a Query

[DoorOpener]

I have some queries in which a field will add 2 other fields and divide by 2 (the only way I know how to do an average function in a query). The problem I am having is with rounding off. I can get the averages to either truncate or show x number of decimal places. The only method I have found to round off is the following:

1) Open query
2) Right click on desired column
3) Choose "Column Format"
4) Change the number format as desired
5) Click "OK"

So far, so good. However, I am supposed to be able to save these changes. None of the save options are available, though.

Using Windows XP, OpenOffice.org 3.4.0.