You could try using windows scheduled tasks:
1) Create “gateway” document in Notes. When user opens this document, real destination form is created and opened for that user.
2) Create .ndl file with link to that “gateway” document
3) Add command to windows scheduled tasks list to launch that .ndl file with appropriate schedule.
New form will pop up even if Lotus Notes is not running.
Weakness of this approach – you need create scheduled task on each desktop 🙁