%set(name,exec)
%set(syntax,%%exec(command)
%%exec(command[\,stdin[\,stderr]]))
%set(description,stdin is passed to the standard input of the app

stderr defines the following macros

     %%err-out%%
and  %%err-code%%
whch contain the "standard output stream" and the "return value" of the app)
%set(author,)
%set(example,)
%set(seealso,)
