Theme/appearance of treeview row separator, paned handle and paned gutter

[kmbruhnk rockwellcollins com]

I'm developing a training application that needs to look as nearly as 
possible to an existing application.  I've already developed a theme which 
accomplishes most of what I need to do.  However, I haven't figured out 
how to theme two particular aspects of two different widgets.

1) Treeview row separator
The default row separator appears to be a thin black line.  I need it to 
be a colored etched in line. I have an image that I'd like to stretch 
horizontally to replace the row separator, but I haven't been able to 
determine how to do this using the pixmap engine.  Can anyone share how to 
do this?

2) The handle placement on the vpaned widget
By default the handle is in the center.  I would like the handle to be 40 
pixels from the right of the vpaned widget.  Is it possible to set this, 
either in the theme or using code? 

Is there a comprehensive theming guide out there that I haven't found yet? 
 It seems none of the themes I see online try to change the things I need 
to change.

Thanks in advance for any help or guidance.

Kurt M. Bruhnke
Email: kmbruhnk rockwellcollins com