All CGI scripts must be placed in your cgi-bin directory. The cgi-bin folder is located in your public_html directory (e.g. public_html/cgi-bin). If you want to run CGI script in a subdomain, put the script the subdomain's cgi-bin directory.
Uploading CGI Scripts
When using FTP, it is very important to upload script files (e.g. .cgi and .pl) in ASCII mode. FTP clients will give you the option of uploading in ASCII, binary, or "auto." If "auto" is selected, then make sure .cgi and .pl are considered ASCII files by your FTP client. Scripts will not execute properly if they are uploaded in binary mode.
Be sure to follow the directions included with the CGI script.