I'm trying to look at a 100mv sine wave with a dc 2v offset, I can't seem to find how to use the vertical position control so I can see my dc off setted waveform.
I remember disconnecting earth and reconnecting to the offset on an analogue scope.
Your proposed method may not work if your probe ground is connected to chassis ground (which it probably is). Are you just trying to get the dc levels of the two signals the same? Or both DC and AC? Or what? Maybe you need to do this in two steps: adjust the dc levels and then adjust the low-level AC.