slur control-points (collides with accidental)

[Jan-Peter Voigt]

Hello List,

I have a figure with a slur, where the slur collides with an accidental. 
So I tried using control-points to move/shape it a little.
Well I still prefer lilys version and have to live with touching the 
accidental, because my shape doesn't look natural and I have to try to 
find the right points.
My Question is, is there a way to get lilys control-points and modify 
them just a little bit?

--snip--
\version "2.12.3"

\relative c'' {
  \time 6/4 \autoBeamOff
  c!8([ fis, g! bes] a[ d, dis gis b! cis]) d! bes
  \once \override Slur #'control-points = #'((0.3 . -0.3) (2 . -8) (13 
. -6.5) (27.3 . -0.3))
  c!8([ fis, g! bes] a[ d, dis gis b! cis]) d! bes
}
--snip--

Cheers,
Jan-Peter