problems with Umlaut for GAEB format

I have a problem for the umlaut in GAEB format.

I needs to transform a xml (ISO-8859-1), into a GAEB format with StringTemplateonPip (output as ISO-8859-1).

I used 2 GAEB software to test the result, GAEB viewer and MWM Primo. The problem is the umlaut of my result can only be recognized by one of the software while the umlaut in original example works for both.( I checked it with HEX editor, ü = 81,Ü = 9A,ö = 94,Ö = 99,Ä=8E,ä=84, who can tell me what encoding it is? I searched a lot but didn’t find.)

So I want to replace it with the umlaut inside the example. I use replace service. but only ü works, which is very strange, because if I replace it by copy, then all of them works well.

I am lost now, the work has overdued and the boss is waiting for it.:frowning:

is there anyone who can help me? Thanks very much

By the way, does anyone know how many encoding (e.g UTF-8, ISO-8859-1) does wm services(e.g StringTemplateonPipe)supported?

we find out the that is a certain dos encoding which shows all the detail in
http://www.kostis.net/charsets/cp437.htm

But the problem is what the name of the encoding in wm service

I think it is ISO-10646 but how to express in WM?