That's not possible or in other words:
Your problem has nothing to do with the setup of that rule - it happened because you used the wrong path once yourself.
Probably you've used that path once and JD now auto-sets it as it is your last used path.
Either change that manually (= confirm one valid path once, this will then be used as last default path again) and/or reset the following advanced setting (Attention: this will clear your history of used download paths):
Settings -> Advanced Settings:
Code:
download destination history
--> Click on the yellow arrow in that line, right side to reset your download path history.