This script takes the currently selected effects and creates new versions
that are linked to the original 'master' effects using expressions.
Copy/paste these new 'linked' effects around your project, then when you
change a value on one of the master effects, that value will also change
on all linked versions in the project.
Note: This script requires After Effects 6.5 or later.
How it works :
1/Select an effect on a layer in TLW or the ECW
2/Apply the script
3/The dialog box to select your options (in this case I left it at the default settings)
4/The result in the TLW
5/And the expressions that were created. Now you can copy the linked effects and paste them wherever needed.