Actually getting the Pro-96 to trunk on a Moto 800Mhz system is so easy, it seems like there ought to be more to do. Of course to get it to only pick up certain TG's, etc. requires more work and can be tedious at the least. I would recommend that you invest the $30 to get the Win96 software from Don Starr (starrsoft.com) and get a programming cable from RS (or other sources). But as it is Christmas day, let's see if we can get you at least going.
I am going to assume that you have a blank frequency bank that you can work in for the purpose of this instruction and that you know the CC frequency that you need to enter for the nearest tower.
1. After the scanner is on toggle all but the target (frequency) bank off by pressing <SCAN> then pressing each number 0 - 9 until only the target bank has its number showing.
2. Press <MAN> then press <FUNC> <TRUNK> this puts you in trunking ID PRG mode. Press the <MODE> button until the display tells you that you are in Motorola mode.
3. Press <PRG>, assuming the bank is empty you should be on slot x00. Enter the frequency, remember the decimal and press <ENTER>. At this point the frequency should go in and the upper right hand part of the display should read MO with either a "+" or "-" next to it. If it doesn't, I suspect that you did not do step 2 correctly. But no matter press the <MODE> button until it does say "MO".
At this point the scanner is able to scan in Trunking mode; however, just to make sure press <MAN> and the bottom of the display should say it is M96 and give you codes matching the Michagan State system data here on the site. In any case if you press <SCAN> it is trunk tracking. If the symbol next the MO is a "-" press <FUNC>, <5> to toggle it to a "+" (OPEN mode) so that you will begin to hear traffic.
Merry Christmas.