We need to add a 1st floor 1/2 bath. My idea is to remove the toilet from the basement (which nobody uses)and install a new 1st floor toilet above, literally using the existing (basement) plumbing... can I run the new toilet waste line into the existing waste line below if plan my bath to be directly above old basement camode? (if so / can I do same with vent system below?)

or am I way off in my thinking?? thanks