This function should be called to execute external preprocessors.
This function does almost nothing else but calls the function epreproc().
int scriba_RunExternalPreprocessor(pSbProgram pProgram,
The argument ppszArgPreprocessor should point to a string array. This string array
should contain the configured names of the preprocessors that are applied one after the
other in the order they are listed in the array.
Note that this array should contain the symbolic names of the preprocessors. The actual preprocessor executable programs, or command lines are defined in the configuration file.
After calling this function the source file name property of the program object (pszFileName) is also modified so that it points to the result of the preprocessor. This means that after the successful return of this function the application may immediately call scriba_LoadSourceProgram().
If there is any error during the preprocessor execution the function returns some error code (returned by epreproc) otherwise the return value is zero.