Create a formula that does the percent calculation.  In the Formula Workshop, you can easily find the report field which does the group summary and the grand total. Double click on each one to put in the the code editor box. Then put the '/' between them to do the division. Here is a sample I did to do a percent of sales by customer based on the total sales for the whole company.

Sum ({Orders.Order Amount}, {Customer.Customer ID})/Sum ({Orders.Order Amount}) * 100.00

Well, you're on the right track and what you've done is what I would have recommended anyway. The problem you are encountering is trying to do a running total and using the Previous() function. First off, are you using the Running Total Expert or creating a manual running total with a formula? I would think that you shouldn't have any problems doing a manual running total. Either way, another idea is to not use the Previous() function and instead replace it with a shared variable the tracks the current DCN. For each record, update it to the new DCN. But prior to updating it, check the current field with this variable and that is the same as comparing it to the previous value (did that make sense?) In other words, put the DCN in a variable so you can see what the previous value of it was in your testing.

You should read my free online chapters. I have examples and explanations there.
Running Totals Tutorial

Near the middle of the chapter I discuss using formulas instead of the running total field.

Yes, you almost have it. You can't summarize the formula because it doesn't hold a value. It's the DCNCount variable inside the formula that you want to display. The formula is just the means for doing the calculations.

The TotalDCNAll formula has the right idea, but i'm confused. It looks like you are using Crystal Syntax, but you are using "=" instead of ":=". That implies you are using Basic syntax. I'm surprised you haven't gotten an error message in the formula about this. I'm going to rewrite it for you and see if that helps out.

Global StringVar DCNNumber;
Global NumberVar DCNCount;
If DCNNumber <> {tblMainResults.DCN} then
(

DCNNumber := {tblMainResults.DCN};
DCNCount := DCNCount + 1;
);
DCNCount;

Then, the formula TotalDCNSum just needs to print the variable that holds the count.

Global NumberVar DCNCount;
DCNCount;

Edited by BrianBischof - 21 Jun 2007 at 10:27pm

Well, I'm a little confused (I'm at work and don't have time to TOTALLY study every question b/c there are so many on the forum today....) Anyway, the best way to reset the variable is to put a reset formula in the group header that sets TotalDCNAll to zero. That way it starts at zero for each group. I don't understand how you can use that Sum() calculation in the formula because you can't sum on another formula. That strikes me as odd that this works. Also, the formula SHOULD be correct for not counting dups because you If Then statement is perfect.

So, all around I'm not sure what to tell you. What I would do at this point is to unhide the detail section so that you can see the value of DCNCount for every record in the report. This will let you look at it line by line and see exactly which records cause it to change value and which ones don't.

Oh! I just realized something. Put WHILEPRINTINGRECORDS in the beginning of the formula. I bet that's the problem! It's doing the calculations while its READING the records. That means that the data isn't grouped yet and that would explain why it starts at such a large number when it begins printing. Yes, try this and let me know if that fixes it. Oh yea, I would still try getting rid of Sum({@TotalDCNAll}) in that formula. It just doesn't sound right to sum a formula and I'm surprised it doesn't give an error (I guess I have to research this one in the future to see what is happening).