You should be able to do this by temporarily changing your code page.

This works for me. Before running it set $iMyCodePage to the right value. You can get it my running "chcp" with no parameters in a DOS window.

 Code:
$=SetOption("ASCII","ON") ; *** Must be in ASCII mode

$iMyCodePage=850 ; *** Set this to your value - use CHCP at command prompt to see what it is
$iWinCodePage=1252
$iEuro=128 ; *** Don't be tempted to use $Euro=CHR(128) here, it won't work.

"Normal code page, euro character : "+Chr($iEuro)+@CRLF

; Switch to code page with euro support.
Shell "cmd /C chcp "+$iWinCodePage
"Windows code page, euro character: "+Chr($iEuro)+@CRLF

; return to standard code page.
Shell "cmd /C chcp "+$iMyCodePage