  We present a method to search low energy configurations of polar molecules in
the complex potential energy surfaces associated with dense fluids. The search
is done in the configurational space of the translational and rotational
degrees of freedom of the molecule, combining steepest-descent and
Newton-Raphson steps which embed information on the average sizes of the
potential energy wells obtained from prior inspection of the liquid structure.
We perform a molecular dynamics simulation of a liquid water shell which
demonstrates that the method enables fast and energy-controlled water molecule
insertion in aqueous environments. The algorithm finds low energy
configurations of incoming water molecules around three orders of magnitude
faster than direct random insertion.
  This method is an important step towards dynamic simulations of open systems
and it may also prove useful for energy-biased ensemble average calculations of
the chemical potential.
