Prior discussion on this site...
http://www.howtomendit.com/answers.php?id=115117
Are you sure the brand is "Rollaway" ?
Page 19 of this pdf might be useful (but might not be)
http://www.liftmaster.de/produkte/download/bas300k.pdf
Found at...
http://www.easygates.co.uk/liftmaster-manuals.asp#garage_door_openers
Size of cable indicates Current rather than Voltage
Does it work if there's a power failure i.e. are there back-up batteries to work the door?
What components are on the control board where the motor wires connect?
Is there a motor start capacitor (AC motor) in the circuit?
Have you considered repairing the defunct control panel?
Your need for a new remote control unit confuses when you say the control panel is defective.
A home engineered solution with just a simple switch might be dangerous without safety devices built in.
I know nothing of electrically operated garage doors.
Good luck...
Peccavi
November 2009