SUM based on boolean range

Question

I really need help summing values based on a range (in an SSRS expression). I have a dataset that pulls accounts and money values.

SELECT acct, location, amt FROM Table

I need help creating an expression for a tablix. I'd like to sum the amt values for accounts lying within a range. For example, I have accounts ranging from 40000 to 99999. So I'd like to do, for the expression:

=IIF(Fields!acct.Value >= 40000 and Fields!acct.Value <= 50000, SUM(Fields!amt.Value), "0.00")

The problem with the expression above is that it is returning the wrong sum. I believe it's summing all available amt values from the dataset when an acct falls between that range. I need it to only sum the amt values that fall between the range. I can't simply make the range smaller, because eventually I am trying to do more calculations on other ranges within the expression, similar to...

=(IIF(Fields!acct.Value >= 40000 and Fields!acct.Value <= 50000, SUM(Fields!amt.Value), "0.00")) 
- (IIF(Fields!acct.Value >= 55000 and Fields!acct.Value <= 99999, SUM(Fields!amt.Value), "0.00"))

I am not sure where to look to see the syntaxical issue with this. Do I throw a boolean within the SUM? Really stuck on this...

Answer 1

=SUM(IIF(Fields!acct.Value >= "40000" and Fields!acct.Value <= "50000", Fields!amt.Value, 0))