You can move a vertex numerically by entering the XYZ coordinates in the "Move to" entries in the Control Panel (on the left, just below the shape/geometry buttons). You can also use the ">" button to capture the current selection's position.
You can deselect vertices using Shift+Right click.
The only way to not select the ones "behind" the vertices you want is to maybe select in the 3D window or fron a different viewpoint. There is an option not to select backfacing surfaces, but this only applies to surfaces, not vertices.
hth
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