\stretched{foo \bar} problems with expansion of \bar

[Tobias Burnus <tobias.burnus@physik.fu-berlin.de>]

Hi,

First I'd like to thank Taco for the calculation work, it works
like a charm :-)

I have a seemingly simple problem (which is probably simple, but I don't
have access to the TeXbook at the moment).

I have:
  \def\Semester{Wintersemester 2001/2002}
  \stretcheduppercase{VORLESUNGSKRITIK ZUM \Semester}
  \bye

Well, the \Semester is not expanded before the stretching is done.

Thus I have
  V O R L E S U N G S K R I T I K   Z U M  Wintersemester 2001/2002
instead of
  V O R L E S U N G S K R I T I K   Z U M   W I N T E R S E M E S T E R ...

Using \stretched instead of \stretcheduppercase produces error messages
(grouping). I experimented a bit with \expandafter, but I failed.

Tobias