Run Dates in iCal and Spotlight Comments

I need help writing a script that takes files (usually pdfs) allows you to input the run dates for for those files into a shared iCal calendar and then copy the dates into the spotlight comments of the file itself.

For example file “7-12345.pdf” is schedule to print in a newspaper on March 3rd, June 6th and Dec 17th based on its run ticket.
How could I automate the process so that by dragging the file on a script it asks for the run dates and transfers the info to a server group shared ical calendar and spotlight comment?