Biff
I have reviewed you equation and I have some questions.

the month function reduces to "01-september" and returns a value of 9. How
does "01-september" become a serial number equal to september?

The inner indirect function reduces to "1:9" which becomes $1:$9. Why does
this happen?

The rows function reduces to 9 which I think I understand.

The text function reduces to 252,"mmmm" which returns september. Why?

The outer indirect function reduces to "september!B9". Why do you use the
sumif function and the sumproduct function?

Thanks

"T. Valko" wrote:

If you'd like, I can put together a sample file that demonstrates both
methods I suggested.


--
Biff
Microsoft Excel MVP


"SmilingSteve" wrote in message
...
Biff
Thanks for your input. I am not intimately familiar with a lot of excel
formula so I will need time to understand what you suggest. I will get
back
to you.

Is there a good reference for how excel processes its functions? Help
gives
the format and explanations of variables but not the how and why it works.

"T. Valko" wrote:

Ooops!

Forgot something:

Enter this formula in J1:
Enter this formula in K1:

Now, select both J1 and K1 and copy down to J12:K12


--
Biff
Microsoft Excel MVP


"T. Valko" wrote in message
...
G7=September

Assuming you will *always* want the sum from January to ???

Try this:

=SUMPRODUCT(SUMIF(INDIRECT(TEXT(ROW(INDIRECT("1:"& MONTH("01-"&G7)))*28,"mmmm")&"!B9"),"<1E100"))

If that's too "obfuscated" then:

Enter this formula in J1:

=TEXT(ROWS(J$1:J1)*28,"mmmm")

Enter this formula in K1:

=INDIRECT(J1&"!B9")

Then your sum formula would be:

=SUM(K1:INDEX(K1:K12,MATCH(G7,J1:J12,0)))



--
Biff
Microsoft Excel MVP


"SmilingSteve" wrote in
message
...
I have an excel workbook with multiple work sheets (Summary, January,
february..., December) On the Summary worksheet I want to create a 3d
reference summing all B9 cells across the monthly worksheets. I can
do
this
for a specified range of months, like =sum(january:December!B9. I
want
the
second reference, December, to be variable, like february or
september.

I tried indirect but it evaluates the string left to right and
consequently
gives me a name error.

Any suggestions as to how I do this?