A bit of help with masks

Hi!
Happy SNS-HDR Lite user here, now considering the Home version.
Just need a bit of clarification with the Masks part, if anyone may shed some light.
I was thinking, for example, that I could mask a face in a portrait, to make the HDR "magic" show up only on the rest of the picture. So I paint the face in green, then try one of the presets, but the effect still apply on the entire image.
Am I missing a flag or a slider or something like that?
Thanks in advance,
Bye!
Happy SNS-HDR Lite user here, now considering the Home version.
Just need a bit of clarification with the Masks part, if anyone may shed some light.
I was thinking, for example, that I could mask a face in a portrait, to make the HDR "magic" show up only on the rest of the picture. So I paint the face in green, then try one of the presets, but the effect still apply on the entire image.
Am I missing a flag or a slider or something like that?
Thanks in advance,
Bye!