I do not think READ_TEXT can be language independent. However, as a workaround you can do this:
Check SY-LANGU = 'DE'.
IF TRUE.
READ_TEXT USING LANGUAGE = 'FI'.
ENDIF.
If there are multiple scenarios like this, you can always use CASE..ENDCASE.
So you get the idea, instead of making it language independent, create the illusion that it is language independent.
Hope this helps.
Thanks,
Soumyajit