Can the SQL statement in a Lookup Transformation be set by a variable?

I'm working with SQL Server 2008 R2.

I'm doing maintenance on a package built by a dev that is not available. In this package there is a Lookup Transformation that pulls it's lookup values from a SQL Query. The query APPEARS to have a hard coded value in the query window...except it appears to be driven by a variable which is weird because I can't seem to find where the variable is set; the editor doesn't seem to have the option of "set query from variable" that I would expect.

In the editor, I can change the query:

SELECT lookupid, matchColumn
FROM lookupTable
WHERE foreignKeyValue = 6

When I run the package and look in the editor again I see

SELECT lookupid, matchColumn
FROM lookupTable
WHERE foreignKeyValue = 1