How do I create a box-plus-arrows combination like this?

I want to create something a bit similar to the attached image file, but applied to the "Sample" file also attached.

In my specific case, I want to create a box that surrounds bar 4, the horizontal text frame with spoken words, and bar 5 (with some free space, like the image). I then want to draw arrows that span the gap left but he horizontal frame.

The aim is to then add instruction that the notes in bar 4 are to be held for as long as it takes for the words in the frame to be spoken.

How do this? Can it even be done?

Thanks :-)