Breaking up html index

I'm working with an application that generates an index file for a web site with up to 50'000 entries. This is o large to be handled reasonably. Therefore the file should be broken up into smaller fiiles with 50 to 100 entries each. I need an application/procedure that - copies each 50 to 100 entires into new files with same header/footer - generates one (or several) index files of the above files with respective links - generates an index file of the above index files (in case of several) - the application(s) must be able to handel 5 differnt types or original index files Input: Original index file, parameter of number of entries in new files, name structure for output file Output:New Index files, file of index of files,