The \\ are ok. I need to use them but I have to send the mail using this code:
system ("blat e:\\xvrt\\edefa.es\\html\\cgi-bin\\msg.txt -t ballenilla\@edefa.es");

where msg.txt is the message I want to send with it full path and blat is the smtp installed in c:\winnt\system32\blat.exe

How I can modify the scripts to use the command "System" ?