Opening downloaded .asp (Citrix ICA) files with Safari

I would like to have Safari, after downloading a Citrix connection file, open the Citrix ICA Client application and then use the file the establish a connection.

In other browsers, you can set this up under "helper applications" or something like that. I can't find where this is done in Safari.

I have Tiger and Citrix 7.02 for Mac. G3 IMAC.

Thank you