Proyection from a mesh to another

Hi everyone,

I would like to know if FreeFEM has some proyection routine between two meshes. The named “A Fast Finite Element Interpolator” computes a interpolation of the meshes but that does not satisfy properties as:
\int_{\Omega} u_{H} = \int_{\Omega} u_{h}
where u_{H} is the solution over a mesh of \Omega and u_{h} is his interpolation/proyection over a different mesh of the same domain.

Is there some function that i could use to implement this kind of thing or do i have to code myself this functions?