stemUp stemDown with chords

[Mark Dewey]

Hello,

I'm having problems with chords and stem direction.

It seems whenever I want one note of the chord to go up and the other to go
down, I cannot specify this with \stemUp and \stemDown (doing it to one note in
the chord will do it to all of them).

How do I make it specific to one note (or one voice)?

For instance, I can't just type the following:

<<{\stemUp d'4 c'2} {\stemDown b4 a2}>>

Now, I can do the following
<<{d'4 c'2} \\ {b4 a2}>>
to get this effect naturally.  However, the need to do this is not always
desirable.  For example, when I type the following:
<< d'2. \\ {c'2 (b4)} >>
I run into the bug where the dot of d'2. is slightly blocked by the note head of
c'2.  If I get rid of the \\ then all the stems face the same direction and
cannot face different directions, it seems.

Anyway, a way around this would be nice.  Anyone know of one?

Thanks!