  We present a framework to control and track the observables of a general
solid state system driven by an incident laser field. The main result is a
non-linear equation of motion for tracking an observable, together with a
constraint on the size of expectations which may be reproduced via tracking.
Among other applications, this model provides a potential route to the design
of laser fields which cause photo-induced superconductivity in materials above
their critical temperature. As a first test, the strategy is used to make the
expectation value of the current conform to an arbitrary function under a range
of model parameters. Additionally, using two reference spectra for materials in
the conducting and insulating regimes respectively, the tracking algorithm is
used to make each material mimic the optical spectrum of the other.
