+ char *ret = NULL;
+
+ int lower = 0;
+ long long int base = RADIX;
+ int exp = 1;
+
+ assert (i >= 0);
+
+ while (i > lower + base - 1)
+ {
+ lower += base;
+ base *= RADIX;
+ assert (base > 0);
+ exp++;
+ }
+
+ i -= lower;
+ i += base;
+
+ ret = xmalloc (exp + 1);
+
+ exp = 0;
+ do
+ {
+ ret[exp++] = (i % RADIX) + 'A';
+ i /= RADIX;
+ }
+ while (i > 1);
+
+ ret[exp]='\0';
+
+ reverse (ret, exp);
+ return ret;
+}
+
+
+char *
+create_cell_ref (int col0, int row0)
+{
+ char *cs0 ;
+ char *s ;
+
+ if ( col0 < 0) return NULL;
+ if ( row0 < 0) return NULL;
+
+ cs0 = int_to_ps26 (col0);
+ s = c_xasprintf ("%s%d", cs0, row0 + 1);
+
+ free (cs0);
+
+ return s;
+}
+
+char *
+create_cell_range (int col0, int row0, int coli, int rowi)
+{
+ char *s0 = create_cell_ref (col0, row0);
+ char *si = create_cell_ref (coli, rowi);
+
+ char *s = c_xasprintf ("%s:%s", s0, si);
+
+ free (s0);
+ free (si);
+
+ return s;