Just to be clear for anyone else reading this, I regard "formatting" as bold, italic, left/right alignment and color. What you're asking about is aligning lyrics and maybe chords in different lines using spaces in your text.
The first thing to know is that you will need to set Settings > Appearance > Lyrics Font to Monospace if you want to align text in this manner. Otherwise every letter will have a different width and it will be impossible to align things accurately.
The other thing is that the sources you're pasting from might use methods other than spaces to align text -- maybe tabs, or HTML tables. BandHelper doesn't support tabs or HTML in its text fields, so if this is the problem, you'll have to realign things using spaces.
If you follow those two steps, the alignment should work reliably.