I would keyframe the move of the cam from left/right or right/left as the crow flies. Then, using the front camera view, add a keyframe in the middle of the move line in the preview window and drag it up (Make sure the scrubber is at the half-way point between the two keyframes). Now the cam move should look like an upside-down V. Change the interpolation of the keyframes to bezier. (Right click on the higlighted keyframes to do this). Also right click on the highlighted keyframes and select ‘Rove across time’
That should do it.