After some good hints via this list i decided to do it the following way.
I recovered the database without the missing files. Some "alter Database datafile ' ' offline drop" did the job. Thx Juan ;-);-)
After that i wrote a small package wich generated the rowid's of the objects we are interested in. Thx Lou ;-);-) Within a small shell script this rowid's generated the SQL 's to read the data into ascii - files. So we were able to put the data via sqlloader into a new database. Not a realy nice way, but it did the job.