But %SystemRoot%_system32_cmd.exe translates to X:\i386_system32_cmd.exe and that's pure nonsense!
I think you did not look at that link yet.
The 'pure nonsence' is a REGISTRY KEY NAME!
BTW: This is WORKING code in my trackWBInstall project:
// give the cmd window a history buffer
RegHiveLoad,"WB-Default","%target_sys%\config\default"
RegWrite,"HKLM","0x4","WB-Default\Console\%SystemRoot%_system32_cmd.exe","HistoryNoDup","1048576"
RegWrite,"HKLM","0x4","WB-Default\Console\%SystemRoot%_system32_cmd.exe","QuickEdit","2048"
RegWrite,"HKLM","0x4","WB-Default\Console\%SystemRoot%_system32_cmd.exe","NumberOfHistoryBuffers","5"
RegWrite,"HKLM","0x4","WB-Default\Console\%SystemRoot%_system32_cmd.exe","ScreenBufferSize","32768080"
RegWrite,"HKLM","0x4","WB-Default\Console\%SystemRoot%_system32_cmd.exe","ScreenColors","15"
RegWrite,"HKLM","0x4","WB-Default\Console\%SystemRoot%_system32_cmd.exe","FontSize","786440"
RegWrite,"HKLM","0x4","WB-Default\Console\%SystemRoot%_system32_cmd.exe","FontFamily","48"
RegWrite,"HKLM","0x4","WB-Default\Console\%SystemRoot%_system32_cmd.exe","FontWeight","400"
RegWrite,"HKLM","0x4","WB-Default\Console\%SystemRoot%_system32_cmd.exe","HistoryBufferSize","51"
RegHiveUnLoad,"WB-Default"
Peter