ok, now there is another problem:
there are also other numbers in the same field, that I don't want to change.
The start like 123456 => they don't have 'de' in the beginning.
Can I use the if-function to check/change only the "de-beginning" numbers?
if (F1 like 'de*', left(F1, 2) & right('0000' & mid(F1,3), 4) as Type; Type)
second Type not to be changed.
Thank you very much your held and answer!