We aim to design an original query language allowing the querying of many heterogeneous workflow sources in a simple way. In a first time, a state-of-the-art on computational workflow query engine aiming to retrieve workflows will be done. It is worth noting that it will be expected a detailed identification of workflow and execution representation requirements (including provenance) together with the assessment of existing workflow and trace stores capabilities. Next, an expressive query language will be proposed considering not only workflow design but also workflow usage. The proposal will be validate by an implementation of a prototype able to query several workflows coming from some sources like \cite{snakemake,nextflow,galaxy} and \cite{workflowhub}. This proposal takes place within the framework of a PEPR 'Santé Numérique' Project, ShareFAIR  https://projet.liris.cnrs.fr/sharefair/