Could you try to word your question better? When you say 16 notes, do you mean that number, 16 notes to a bow (if so, what kind of notes are they, quarter, eigth, etc.)? Or do you mean you want 16th notes under one bow (if so, how many 16ths). If you're looking to have a run of notes under one slur and wanting to accent one single note (which note, the 1st, 6th, 13th, etc.?), it would be possible, shouldn't be difficult. The violinist would just pull the bow extra or add some bow weight to the note. Ease may depend on what kind of notes they are; the faster they are the more difficult but not ridiculously so.