Actually, the substring function should be SUBSTRING(name,1,2) == "ab".

If you use a single = sign, SSIS assumes you are assigning a value to something. == is the true conditional test of whether or not something equals another value.

Good catch on the single quote problem of the previous poster.

EDIT: I know this is an old thread, but I added my bit in here in case anyone else comes across this thread in a GOOGLE search and tries to use the solution in their package.