editing ornament playback

I'm wondering if there's already a way to change what an ornament does in terms of playback--I'm transcribing some music that's very heavily ornamented,and one of the most common ornaments is so mordent-like that I have been using it to reduce notational clutter. However, it is rhythmically a little different and it makes it both hard to aurally check my work and a little unsatisfying to have this slightly off element occur so frequently. Is there a way to massage the rhythmic value of an existing ornament, or to create a new one? If not, I suggest there be.