Now If only my 20-year-old FBQ2496 had a high pass and a low cut. I set a deep one-octave notch at 20 Hetz and it sounds like a high-pass to me. I am very impressed. In manual, I have added it to my 24bit/96k audio chain and it sounds clean live. I ordered a couple of Midi cables so I can use REW to connect my UMC404HD audio interface to it. Finally a productive use for my Midi in and out ports.Using the EQ Window is explained in the help, there is not a great deal to do - make the measurement, select the target shape and set the target level, choose the frequency range over which you want REW to generate filters, and click "Match Response to Target". REW will then generate a set of filters to use.
The DEQ looks to use the same filter BW settings as the FBQ, so selecting FBQ2496 as the equalizer may give you suitable settings to use. It would be best to check first though, the most reliable way would be to make a measurement with the DEQ2496 output fed to the soundcard input and a filter set up, then compare the shape of the filter to a filter in REW with the same settings.