Cisco AP Signal Strength

Hello, I would appreciate a little help setting up a custom SNMP sensor to monitor signal strength on a Cisco 1532E wireless bridge device. I went through and found the OID and created the oidlib via the MIB Importer. I then saved it to \snmplib. So, I think I'm good there. I first tired to create the sensor, I used a Custom Sensor - SNMP Custom sensor type and put in the OID I found in the MIB (1.3.6.1.4.1.9.9.273.1.3.1.1.3). But, I got SNMP error #223. Basically, it didn't know what I was asking for. So, I downloaded the SNMP Tester and did a Walk of the OID listed previously. Here are the results:

----------------------- New Test -----------------------

Paessler SNMP Tester 5.2.3 Computername: CDCMS130 Interface: (10.1.4.30)
8/10/2016 12:21:30 PM (1 ms) : Device: 10.1.75.10
8/10/2016 12:21:30 PM (1 ms) : SNMP V2c
8/10/2016 12:21:30 PM (2 ms) : Walk 1.3.6.1.4.1.9.9.273.1.3.1.1.3
8/10/2016 12:21:30 PM (4 ms) :1.3.6.1.4.1.9.9.273.1.3.1.1.3.1.9.67.68.67.66.114.105.100.103.101.240.178.229.221.98.32 = "-66" [ASN_INTEGER]

See that "-66" listed at the end? That's the number I want to display in my monitor. That's the same number you get if you run "show dot11 associations all-client" on the WAP.

NOW, here's the issue: When I put that big long OID in the "Custom OID" field in the SNMP tester, I get this:

----------------------- New Test -----------------------
Paessler SNMP Tester 5.2.3 Computername: CDCMS130 Interface: (10.1.4.30)
8/10/2016 12:24:13 PM (1 ms) : Device: 10.1.75.10
8/10/2016 12:24:13 PM (1 ms) : SNMP V2c
8/10/2016 12:24:13 PM (2 ms) : Custom OID 1.3.6.1.4.1.9.9.273.1.3.1.1.3.1.9.67.68.67.66.114.105.100.103.101.240.178.229.221.98.32
8/10/2016 12:24:13 PM (5 ms) : SNMP Datatype: ASN_INTEGER
8/10/2016 12:24:13 PM (6 ms) : -------
8/10/2016 12:24:13 PM (7 ms) : Value: 4294967230 (OK)
8/10/2016 12:24:13 PM (8 ms) : Done

That Value (4294967230) is somehow related to the -66 value I received above. I want to display -66 in the monitor (or 66 would also be fine). I tried just dividing the two numbers and I got 65075261. I found that I could display 66 in the monitor if I put this in the Divide field. But, I'm not sure that's actually right.

Here's why: A wireless bridge is two sided meaning there's two AP's connecting the buildings. When I try to do the same thing on the other side, I don't get the same 65075261. I run the Walk on the other side and get -69. When I then run the Custom OID I get 4294967227. A simple division yields 62245901. Since this number does not match the 65xxxx number from above, I can only assume that this is not a correct way to determine the value I"m looking for.

SO....How does one get the correct value to appear in the monitor?

cisco-ap custom-snmp-sensor mib-importer snmp-tester