In your RAW converter set the exposure right for the FG and then the BG. Send them to PS, with the two images displayed there hold the shift key down and drag the darker images over the other. Now select the brush tool set to colour black and processed the paint back the FG at 100% opacity. Once you get to where the sky meets lower the opacity until you get a neat seamless joint.
If you paint back to much then switch to the colour white, this will take it back to the original image.
Though not sure if you can do this in your version of PS.
HTH