1-2 shift problem

I have an 87 jeep cherokee with an AW4 trans. I heard there is a device that will allow you to shift from 1 to 2 using the power comfort switch. I do alot of wheeling and would like to keep the tranny in 1 and shift to 2 on my own terms. Any help out there on where I can find this?

if you search there is a lot of info:
http://go.jeep-xj.info/HowtoAutoSwitch.htm

there used to be a company that made a unit. It was called compu-shift or something like that. A great unit u just had to connect the color coded wires to your TCU and bam. good luck.