Add a Vertex (Ctrl-left click), and set the vertex location to origin: ShiftS t (Selection to Cursor)
Press g to enter grab mode. Enter movement in x direction with 0-9 decimal point . and negativ -, Tab enter y value (like the x value), Tab enter z value (like the x value).
Alternatively, you can limit the transform on a axis by pressing x, y or z in grab mode. Or Shift and x, y, z to limit on the other axis .
