Generate a REAL Random number in C

I've got a little problem with the generation of a random number in C, could you help me?

Here is my function so far, how can I make it better?

char newChar() {
    int random;
    srand((unsigned int) time(NULL)*getpid());                                                  
    random = rand()%20;
    if(random==0) return 'A';
    else if(random==1) return 'B';
    else if(random==2) return 'C';
    else if(random==3) return 'D';
    else if(random==4) return 'E';
    else if(random==5) return 'F';
    else if(random==6) return 'G';
    else if(random==7) return 'H';
    else if(random==8) return 'I';
    else if(random==9) return 'L';
    else if(random==10) return 'M';
    else if(random==11) return 'N';
    else if(random==12) return 'O';
    else if(random==13) return 'P';
    else if(random==14) return 'Q';
    else if(random==15) return 'R';
    else if(random==16) return 'S';
    else if(random==17) return 'T';
    else if(random==18) return 'U';
    else if(random==19) return 'V';
    else return 'Z';
}