There is a worksheet for each month of the year and I am trying to sum on the
13th sheet based on a random "from date" and "to date". I am having trouble
creating ranges in the formula that span the 12 monthly worksheets. I
couldn't get named ranges to work.

what I have so far:

=SUMPRODUCT(--(?range?$E$1:$AI$1=DATE(2006,3,3)),--(?range?$E$1:$AI$1<=DATE(2006,3,20)),--(?range?))

where "?range?" is what I am tying to figure out...
Ultimately I will change the dates to reference cells on sheet 13 for the
"from date" and "to date" values.

In sheets 1-12 columns represent days of the month (E2 is day 1, F2 is day
2, etc), rows represent dollar amounts (E3 is $ amt for day one, F3 is $ amt
fo day 2, etc.) and are consistant in each sheet (besides the total days in
the month)

There are around 100 rows on each sheet

Example: Begin date is Feb 25, end date is March 5, I need all rows summed
for the range of columns that are within the from and to date range for
sheet 2 and sheet 3, an example of a sheet for 3 is below:

3/1 3/2 3/3 3/4 etc.
category 1 50.00 5.00 2.00 3.50
category 2 1.00 10.00 .75 .25
around a 100 more categories ongoing below

I need the formula result to show on sheet 13.

category 1 total here
Category 2 total here
etc. etc.

Thanks!