Hi Mikael, I think I showed you how to select all notes on a single line by clicking in the column to the right of it. To select multiple lines, hold down the [shift] key and then click on each line, you can see that each note on the lines become selected
If you haven’t checked out the BBMO user manual, you might want to do so; p15, item 22 will help you.
Follow that up with this link:
I’ll see what I can do in the next couple of weeks. If I don’t work it up in Am, you should be able to easily transpose it with your new found skills in the BBMO 
I finally had time to sit down and figure this transposing thing out and was able to transpose a bassline. Thank you for helping me out. I have the manual and been trying to work my way through it, but my brain struggles with manuals. Your screenshot helped me see where I was supposed to be clicking. I appreciate you. Thank you.
Glad to hear you transposed it to Am. Don’t hesitate to ask more questions.
I’ve finished the acoustic version of the song and will post it sometime next week.