hopefully someone can help me with the following problem.

i have a workbook that contains a number of worksheets, let's say 5; 3 worksheets have formulas to calculate a result, with results from worksheet 1 and 2 displayed on the 4th sheet. a 5th sheet contains a table of data that is used by the 3 calculation worksheets.

worksheets 1 and 2 must be calculated before worksheet 3 as these results are used in worksheet 3. the result of worksheet 3 is then used in recalculating worksheets 1 and 2, with the recalculated result displayed on sheet 4.

how can i exclude worksheet 3 extracting data from sheet 5 when worksheet 1 and 2 is calculated first time? and how can i then calculate worksheet 3 so that worksheet 1 and 2 are recalculated?

i'd rather use a formula than a macro, so is there a way to have a "calculation counter" or "flag"?