I tried is to make a script with things like addkeys, deltrees and writevalue's. Just like you did SLM But all this doesn't work.

After that, I exported the registrykeys from Hkey_current_User and Hkey_users to a regfile. I placed this file in the logon directory. I am now trying if this works
With SHELL "%COMSPEC% /e:1024 /c Copy @Ldrive\Algemeen\Toetsenbord.reg c:\windows\temp"
and
SHELL "%COMSPEC% /e:1024 /c c:\windows\regedit -s c:\windows\temp\Toetsenbord.reg"

If this doesn't work i want to try if i can change the value of the "layout file" in the following key: [HKEY_LOCAL_MACHINE\System\CurrentControlSet\control\keyboard layouts\00000409]
"layout file"="kbdus.kbd"
"layout text"="Verenigde Staten 101"

in "layout file"="kbdusx.kbd"

I hope it works. If it does i let you know...