Hide unsupported language in Unicode NSIS selection dialog

Hello, I am writing a NSIS script for my application. Because it has 2 languages in it (English and Chinese). So I wrote below code:

; Unicode NSIS
; MUI
!insertmacro MUI_LANGUAGE "English"
!insertmacro MUI_LANGUAGE "SimpChinese" 

It works well in Windows XP which has installed East Asia language pack. But, without East Asia language pack installed, it will show garbage chars.

How do I hide Chinese in Selection dialog when NSIS installer run under Windows XP without East Asia language pack?

Thanks.