Matching stems/slurs on mutliple voices

[Hans Forbrich]

How do I set this up correctly: going from a joined dotted-quarter note
to 3 part divisi flagged eigth note, I need to play with the visibility
and stem lengths.  In effect, what I have is:

v1:  cis4.  () fis8
v2:  cis4.  () cis8
v3:  cis4.  () a8

When I place these all on the same staff, I need to

1) supress the "cis4." notehead & stem from v2 & v3
2) suppress the "cis4." dots from v2, v3
3) suppress the "cis8" and "a8" stem and flag from v2, v3
4) lengthen the "fis8" stem (and move the flag) from v1
5) fiddle with the direction and placement of the v2, v3 slurs

No problem with 1, 3 & 5 - but I can't seem to get 2 & 4 right.
Hints/pointers/solution greatly appreciated.

TIA
/Hans