Voice leading lines across staffs

Does anybody know how I can put in voice leading lines when melody lines cross from one staff to another? (e.g. from bass to treble and back again - see picture) The closest I can find is to put little arrows in showing where the melody line goes, but the convention is simply to have a line from the treble note down to the next bass note (or vice versa), not arrows. Moving the notes to the other staff isn't an option, because this is for handbells.

Thanks for any suggestions!

Dorothy