Global Change Implementation on "Finish Date Column"

Guys,

I’m just wonder if we can do global change on "finish date column"

What I did, I imported the excel data onto user_end_date(my forecast date) I want to use global change something like this:

If user_end_date bigger than XXX
Then Finish date = user_end_date

but the problem is I didn’t find "finish date" column instead planned finish date.

so is it we can’t change the finish date automatically?

thx