Vixen Sky Sensor date problem

I have one of these that I pulled out of my closet and would like to use it again. Trouble is that when you start it up it wants the date and only takes 2 digits for the year. The Vixen tech says he's only seen pictures of this unit but that it could only go to 1999. He says he thinks there is a workaround but doesn't know what it is. Anybody out there have any info about this problem?

thanks,
Allen