how do we call a c function from an sql script

int get_next_fbill_b2kId_seq_num(b2kIdType seq_val,bankIdPtrType bank_id)
{
    validate_dc_alias(dcAlias);
    tbaDateType sysDate;
    tbaGetSystemDateTime(sysDate,NULL,NULL);  /* returns in TBA date format */
    sysDate[10] = EOS;
    get_seq_value(next_num_char, 0, FBILL_B2KID_SRL_NUM,bank_id,TBAFATAL);
    m_sprintf (seq_val, "%s%s%s", dcAlias, sysDate+8,next_num_char);

    return(SUCCESS);
}