Use lemon parser(LALR) generate a calulator, how to get param from expressions

I want to get param from a input, for example:Input:12+10,After running my clac,I want to get 12 and 10.I know use the fourth param in Parse(pParser, hTokenID, sTokenData, pArg);but how?sorry, I am new learner in lemon,here is my code: parser.y: %syntax_error{fprintf(stderr, "Syntax error\n);} %left PLUS MINUS. %left TIMES DIVIDE. program ::= expr(A).{printf("Result = %d\n", A);} expr(A) ::= expr(B) PLUS expr(C).{A = B + C; } expr(A) ::= expr(B) MINUS expr(C). {A = B - C; } expr(A) ::= expr(B) TIMES expr(C). {A = B * C; } expr(A) ::= expr(B) DIVIDE expr(C). {if (C != 0)A = B / C;else fprintf(stderr,"divide by 0");} expr(A) ::= LPAR expr(B) RPAR. {A = (B);} expr(A) ::= INTEGER(B).{A = B;} calc.c: int main(int argc, char ** argv){ pParser = (void *)ParseAlloc(malloc); for (c = argv[1]; *c; c++){ switch (*c){ case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': for (value = 0; *c && *c >= '0' && *c <= '9'; c++) value = value * 10 + (c - '0'); c--; Parse(pParser, INTEGER, value); break; case '+': Parse(pParser, PLUS, 0); break; case '-': Parse(pParser, MINUS, 0); break; case '': Parse(pParser, TIMES, 0); break; ...(the rest case I dont write anymore,the same as before) } } Parse(pParser, 0, 0); ParseFree(pParser, free); }