How To "load To New Instrument Box" From Outside?

hi. i’ve got a wavefile. i’ve got a song i’m working on. it’s got 8 instruments, and 8 instrument slots in the instrument box.
i’m in Finder, and have configured all wavefiles to be opened by Renoise 2.8. Now when I press CMD-Down-cursor, Renoise pops up and immediately loads the sample.
This is pretty neat. :walkman:
But i’ve got 8 instruments, and 8 instrument slots. I don’t want to overwrite the instrument my cursor is on currently (the one that I was just playing, and which I just recorded some notes onto the pattern).

How do I make Renoise behave in such a way that when a new sample is loaded, it never overwrites the current instrument box instrument, please?