+const char* MakeHexArg (unsigned Num);
+/* Convert Num into a string in the form $XY, suitable for passing it as an
+ * argument to NewCodeEntry, and return a pointer to the string.
+ * BEWARE: The function returns a pointer to a static buffer, so the value is
+ * gone if you call it twice (and apart from that it's not thread and signal
+ * safe).
+ */
+