Hi Lesley,
BIAB will do it. The easiest way to put it in is to use Piano Roll mode and to drag the right edge of the note across 4 bars. (See the image below.)
Also, here's a PG Music video clip on using the piano roll mode. While it's using an older version of BIAB, the process is identical today.
https://www.youtube.com/watch?v=V97VYOeotmkTo be honest, though, it's very unlikely that the note needs to be written as a hold for four bars. Depending on the tempo of the song, that would drain the wind out of most people's lungs. Usually a bar to 2 bars is a reasonable length to hold. (It's possible that the 4 bars is simply a musical convenience rather than a performance indicator.)
Regards,
Noel