This sounds like the perfect opportunity to learn about pivottables.

Make sure your data has a header row.
Say your data is in A1:C999
Select your data (a1:C999)
Data|Pivottable (in xl2003 menus)
Follow the wizard until you get to the step with the Layout button on it.

Click the Layout button
Drag the header for the custcode to the row field
drag the header for the date to the row field
drag the header for the amount to the data field

If the amount says "count of", double click on it and change it to "sum of".

Finish up the wizard.

You'll have a nice summary table, but with entries for each date.

So rightclick on the Date header
Choose Group and show details
Then choose Group
Group by Months (or Years and Months???)

The nice thing about the pivottable is that you can rearrange it to create
different views into the data.

If you've never used pivottables, here are a few links:

Debra Dalgleish's pictures at Jon Peltier's site:
http://peltiertech.com/Excel/Pivots/pivottables.htm
And Debra's own site:
http://www.contextures.com/xlPivot01.html

John Walkenbach also has some at:
http://j-walk.com/ss/excel/files/general.htm
(look for Tony Gwynn's Hit Database)

Chip Pearson keeps Harald Staff's notes at:
http://www.cpearson.com/excel/pivots.htm

MS has some at (xl2000 and xl2002):
http://office.microsoft.com/downloads/2000/XCrtPiv.aspx
http://office.microsoft.com/assistan...lconPT101.aspx



Charles wrote:

I have a sales order spreadsheet that gets updated daily from our ERP system.
The worksheet has the following columns:
1. Customer code (each customer could have several entries per month)
2. Order date (the current worksheet has two years of history in addition to
the daily updates)
3. Amount

What I would like to do is make a new worksheet that has the following
columns:
1. Customer code listed once for each customer
2. Total sales summed by month ( so I would have a column for each 2 years
of history and will add each new month)

I know I could do this with a pivot table but for internal company reasons I
would like to know if anyone can tell me how to do it with a formula.

Thanks in advanced for your help!!!
Charles

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Dave Peterson