This Scilab toolbox give the possibility to overload user-defined macros as if they were built-in functions.
It was developped in
Fortran so the execution of the overloaded macros is as fast as the common macros (on my computer the overhead by call is near 0.006 millisecs).
Yann and Allan made few modifications to have a Windows version but the toolbox must be compiled with Scilab built from source files.
Take a look :