Creates an index of a program file and stores it as another program file as indicated by INDEXNAME. This is for use with the following command, LookupIndex
Any pre-existing files will be overwritten automatically, as if to update the index, so please take care that an important file is not specifed. If the new index cannot be fit in memory after the old one is deleted, a new one is not created. Unfortunately, you will have lost the old index. Keep a tight rein on memory.
The index is created from FILENAME and stored in INDEXNAME, if enough memory exists.