script task's value for query isnt used in data flow

Hi. We run 2012 enterprise.  To get around the 4,000 limit on var expressions (yes even if I break it up into 3 vars and concat in an expression it doesn't work) I wrote a c# script whose 1 line of code u see below. 

The var Query has an initial value (set in variables view) that selects 1 row with a bunch of zeros. 

The dft that runs after the c# script is coded to use the value in the Query var but instead used the bogus 1 row selector query I used as an initial value.  What is wrong?  The target is read write.  The other 3 vars are read only.  c# is supposed to be immune from the 4000 character limit.

We use vs2008 which makes me think old BIDS restrictions may be in play anyway.

Dts.Variables["Query"].Value = Dts.Variables["Query1"].Value.ToString() + Dts.Variables["Query2"].Value.ToString() + Dts.Variables["Query3"].ToString();