There is no way to reference such connections. This is because you can only reference COM objects from VBScript, and the DTS package is not a COM object, but itself a script. Scripting is included to allow you to access objects in the operating system environment.
If you want to run SQL queries against a DTS connection, you want to use a SQL Query task, which operates against whatevery connection you attach it to.
If your goal is moving data between files and/or tables, you want to use a transformation task between two DTS connections (select the source, holding SHIFT, select the second, then click the Transformation Task button on the toolbar.