iCal feed for custom fields

Hello,

is it possible to have an iCal feed for custom date fields, like those for start and due dates? I have added custom fields to contain appointments with the user etc. for some tickets, and I would like to make them available via iCal as well.

Would it be possible to write an extension for that? I am not very familiar with perl, but if it’s not too complicated I might give it a try,

Thanks,
Andreas