Looping path animation

Hi,

I am curious.  In my animation I have 40 plus different shapes which need to be animated using path property. All need to be looped also.  I wonder do I have to keep pasting 'loop path keyframe expression' to them all individually?? what if it was 100!

Or there is any way I can use a slider where I can write the expression and link path property to that instead of copy pasting so many times!  am I imagining too much! is it far fetched?

Thank you.