Put aliases like the following in your .cshrc file.
alias twn_EUC "setenv LANG zh_TW; /bin/stty cs8 -istrip defeucw" alias twn_BIG5 "setenv LANG zh_TW.BIG5; /bin/stty cs8 -istrip defeucw" alias asc "setenv LANG C; /bin/stty cs7 istrip defeucw" alias twn_UTF-8 "setenv LANG=zh_TW.UTF-8; /bin/stty cs8 -istrip defeucw" |