I have some style adjustments for the chapters. The chapter "numbers" need
to be Boek I, Boek II, etc. A vertical separator was introduced with an
inframe. The chapter title at the right side does not vertically align
properly with the chapter number in the frame (inside the frame is
vertically centered, the title not). Is there a way to align the chapter
title with the chapter number?



\starttexdefinition MyNumberChapterCommand #1
    \inframed[frame=off,rightframe=on,framecolor=black,
     rulethickness=1px,height=30pt]{#1\enspace}
\stoptexdefinition

\setuphead[chapter][style={\bfc},numbercommand=\MyNumberChapterCommand,
    page=no]

\starttext

\startchapter
  [title={Algemene Beginselen},
   ownnumber={Boek I}]

\samplefile{tufte}

\stopchapter

\startchapter
  [title={Organisatorische Structuren},
   ownnumber={Boek II}]

\samplefile{tufte}

\stopchapter

\stoptext