Matlab string insertion emulation function
Matlab and Scilab insertion behave differently for strings due to the fact that they do not consider character strings in the same way.
The function str = mtlb_is(sto,sfrom,i,j) is used by mfile2sci to replace insertion operations for character strings. This function will determine the correct semantic at run time. There is no replacement possibility for it.
Caution: mtlb_is has not to be used for hand coded functions.