Event Reminder Email?

I have a custom flexinode that I have created for logging my company's phone calls. I have information like phone numbers, the date/time of the phone call, duration, client, etc. I would like to make a field for date/time that would remind that user via email at a date they specify for a "client callback". I am pretty sure this is possible since the signup module can interface with the event module and send out a reminder at a specified date. I am only hoping that I can do this with a form that asks for a date and time when the reminder email needs to be sent to the user making the report. Does anyone know if this is possible? Also is it possible to do this without the event module seeing it as an "event"?