  We introduce a novel strategy, based on the use of modular variables, to
encode and deterministically process quantum information using states described
by continuous variables. Our formalism leads to a general recipe to adapt
existing quantum information protocols, originally formulated for finite
dimensional quantum systems, to infinite dimensional systems described by
continuous variables. This is achieved by using non unitary and non-gaussian
operators, obtained from the superposition of gaussian gates, together with
adaptative manipulations in qubit systems defined in infinite dimensional
Hilbert spaces. We describe in details the realization of single and two qubit
gates and briefly discuss their implementation in a quantum optical set-up.
