This is a strange relationship.
Normally when you have 30 odd fields relating to a particular field you would have them in a related table on a seperate row each, this would make your query very straght forward with a Group By clause.
In this sutuation a SUM will not work as you intended because it is meant to sum relational data.(Experts please confer)
In your situation your query should look something like below.
Select (ClickThru1 + ClickThru2 + etc ) FROM ecastdata WHERE EcastID = @strEcastID
If the number of fields, ie 30, is set in stone then this approach is fine, if you may one day need 31+ fields, try a related table asap
They say, best men are molded out of faults,
And, for the most, become much more the better
For being a little bad.