cross-voice slurs?

[Graham Percival]

Is there any way to make a slur between voices?  Or can you make a slur
attach to an invisible rest (or space?)

I'd like to attach each consecutive pair of 16th notes together with a
slur, but I the 16ths need to have alternative stems as well (up down
up down).  I _could_ do that it one voice (ie \stemUp d \stemDown d
\stemUp ees \stemDown d...), but that would be a pain.

----
\score{ \notes{
\clef bass
\relative c {
<{[d16^#"II" s d] s [ees s d] s c s } \\
 {s16 [d_#"III" s d] s [d s d] s d-. }>
r4 d4->
}
}\paper{}}
----

Cheers,
- Graham