It looks like Yahoo is not giving us any environment variables to work with. EditWrx uses environment variables to locate all of the files in the domain path.
With luck we may be able to trick the system to use relative paths instead of the absolute paths that would be in environment variables.
1) Rename wrx.cgi to wrx.pl. That script knows it's own name so you do not need to make any other changes.
2) Make certain that the $editwrx_folder_name variable on wrx.pl is set to the name of the folder that you have the /library and /ikons folder in
3) Add a new line above the line containing $editwrx_folder_name with the following code:
BEGIN{$ENV{'DOCUMENT_ROOT'}='../'}
if your wrx.pl is located in a cgi-bin folder outside of your site's home folder, you need to change that '../' path to a relative path that will point to the home folder for your domain. For example, if your home page is located in a folder named "htdocs" and the cgi-bin is located on the same level as htdocs then the path would be '../htdocs'.