int QSdelete_named_columns_list(QSprob p, 
                                int num, const char **colnames)

/* Assume p is an initialized LP problem.  */
/* Delete variables v and w.               */

int rval;
const char *dlist[2] = { "v", "w" };

rval = QSdelete_named_columns_list (p, 2, dlist);
if (rval) {
    fprintf (stderr,
             "could not delete variables, error code %d\n", rval);
}