SSRS 2008 custom code to properly calculate sums

Hello everyone,

I have a unique issues that I've been trying to resolve with SSRS 2008 using custom code.  Here is my situation: I have a dataset that pulls in test counts and names. so an example would be:

subject | test name | count

CEP 8 | 2R | 10

CEP 8 | 2R | 12

CEP 8 | 2R | 25

In my report, I have a totals section that tallies the count grouped by subject so it would show as:

CEP 8 | 2R | 37

Here's the tricky part and the reason I need to use custom code.  Instead of calculating all three counts, I want it to only calculate the closest 2 counts so it would look like this:

CEP 8 | 2R | 22

I'm baby-stepping the process by slowly modifying the custom code bit by bit so that I can perform calculations to determine which 2 counts are the closest, however, I'm stuck on baby-step #1 in that I can't get data to persist. Meaning I can't even get the correct sums to calculate when I pass the count through the parameter into the custom code.  Here's what I have so far:

public dim values as system.collections.arraylist = new system.collections.arraylist()
public dim variantSum as double

public Function AddValue(ByVal newValue As Decimal) As Decimal

	values.add(newValue)
	
	for i as integer = 0 to values.count - 1
		variantSum += values(i)
	next
	return variantSum
End Function

and my expression for the field I want to show is:

=code.AddValue(Fields!NORMAL_COUNT_1.Value)

Needless to say the calculated numbers are way off.  I feel if someone can point me in the right direction that I could figure this out.  My main obstacle right now is calculating the right sums even disregarding the closests 2 of 3 counts.  If I can get the sums to display properly, I can work the finding of the 2 closest values.

Help!

thank you