There is an undocumented feature that can raise and lower notes in the scale.
I haven't included it yet in the documentation, so it probably has some issues ;)
For a major scale, you should be able to write "V_R1" to get an augmented dominant chord. The 'R1'-part raises the 2nd of the scale, which in this case happens to be the fifth in the chord.
You can also use 'L' in the same way to lower scale notes.