sends an array of null-terminated char* to ngspice.dll. Each char* contains a single line of a circuit (Each line is like it is found in an input file *.sp.). The last entry to char** has to be NULL. Upon receiving the array, ngspice.dll will immediately parse the input and set up the circuit structure (as if the circuit is loaded from a file by the 'source' command). The function returns a '1' upon error, otherwise '0'.