There are several things you should consider when making these measurements. It will be difficult to perform a one button operation.
CISPR 15 has two limits for each detector type, average and quasi-peak. The screen shots that you have shown are of swept measurements. The detector types are average and peak. The Agilent SA shows a span of 150 kHz to 30 MHz with a resolution bandwidth of 120 kHz. The CISPR bandwidth should be 9 kHz not 120 kHz. For the 9-150 kHz range, the bandwidth should be 200 Hz.
For the R&S screen shot, 9 kHz to 30 MHz, a CISPR bandwidth of 9 kHz was used. This is only correct for > 150 kHz. Also, the peak trace data shown is just that peak. In order to compare it to the limit, quasi-peak measurements should be performed. If the peak data is less than the quasi-peak limit, one can assume compliance.
The method for measuring the Voltage Division Factor for the LISN/AMN is detailed in CISPR 16-1-2
I see that you are also on the VEE forum. Your best bet is to write software to do this for you.
You can find how to perform a conductive measuremt, and it includs the process of connecting the system, loading average and quasi-peak and average limit, loading correction file, performing measurement.
Refer to EMCO model 3825/2 LISN, I don't have a exsit correction file for it. I think you can create a correction file according to this LISN's datasheet.
Once you have the correction data for your LISN the easiest way to enter this is to do so with the onscreen limit editor. It's very easy to use. Go to Meas Setup, Limits, Edit.
Or, if you have software version A.10.00 or newer go to the My Documents/EMC Limits and Ampcor/Ampcor folder and start by transfering the LISN, 10A.csv sample file to your PC and edit it for your LISN.