If I understand pgc's suggestion, it requires VBA.
For a simple example, consier a workbook with two sheets, Sheet1 and Sheet2.
In Sheet2!A1, enter =RAND().
In Sheet1!A1, enter =Sheet2!A1
Press F9 and watch Sheet1A1 -- it recalculates, as you wold expect.
In the VBA Immediate window, enter Sheet2.EnableCalculation=False
Now pressing F9 has no effect.
To recalculate Sheet2, Sheet2.EnableCalculation=True, then back to False