Hi,
It is possible to do what you want to do and you dont need an automatic. I have a Mitsubishi EVO 7 with Remote start. The Remote start however is part of the Clifford Avantguard 4 alarm system. Its called Clifford IntelliStart.
The way it works is as follows.
When you park your car you press one of the buttons on the alarm remote while the engine is still on. This will arm intellistart. You then remove the keys, The engine will stay running. Get out of the car and close the door. Then main Arm/Disarm button on the remote is pressed and the car locks, alarm arms and the engine switches off. This precedure ensures that the car will not be in gear when you press the autostart button the next morning. You would have had the car in neutral to get out while the engine was running!
Go to
www.clifford.com for more details.
Hope this helps!