You can drop one friendly stack onto another friendly stack in another region, to create an intercept situation. However, if the target stack resides in a structure, then you cannot create an intercept.
The only work around which I have found is:
(1) Move the target stack from inside the structure to outside the structure.
(2) Create the intercept.
(3) Move the target stack back into the structure.
This seems a little convoluted and non-obvious to me.