How to ä,ö,ü

Dear lout-users,

i tried to write an report in german language.
I used the command line

> lout file.lout -o file.ps -e Bell.err
>
to do export my file.

When my File contains a Ä or similar it renders a strange glyph which is
not selectable.

As a temporary hack i defined macros for each Letter I need.

> macro @ae { @Char adieresis }
> macro @Ae { @Char Adieresis }
> macro @oe { @Char odieresis }
> macro @Oe { @Char Odieresis }
> macro @ue { @Char udieresis }
> macro @Ue { @Char Udieresis }
>
But writing {@oe} takes way longer than just ö.
I attached all relevant files.
Is there an more elegant (read short) way to handle such letter?