Hopefully cleancondenser will respond. He is the metasys master. He can help you out.
Here is a DX9100 Metastat slider setup I have used in the past, it may not be correct for the the slider you are using.
Measurement Units = 0
Type of Active Input = 2
High Range = 7.4
Low Range = -5
High Limit = 100
Low Limit = -10
Filter Cont = 0
Limit Diff = 2
The Rest = 0
I was looking at the metastat, product info and this looks like it may be right, anyway it will be a good place to start.
I am not sure if this would even work...? But-
How about using TE-6700 series room sensors with the warm cool adjust?
Might (can) they work somehow with the DX-9100 AI's?
You can use the TE-67NT-1N00. The product cut-sheets will guide you through the install. Both inputs will be passive AI's, as the slider is just a straight potentiometer. Set your desired range on the passive AI and your good. Hope this helps.
seems to me the sensors are 1kohm. If the slider is anywhere near this any old passive input would do. Just see what values it gives and plug them into a segment module for your output. If you want setpoint with the slider for for plus/minus add a calc module.