Combining split mkv files

[mas_astra]

Periodically I have come across large MKVs (30+ GB) that have been split into smallish parts (26 MB) resulting in file extensions that have 4 digits, i.e. FILENAME.mkv.1001 and higher. Is it possible to add a feature that will rejoin these back into a single MKV? The file splitter/joiner apps that I have seen only allow for 3 digit numerical extensions, starting with 001 through 999, or will place the 1001 (and higher) after the 100 part, resulting in an inaccurately rejoined file.
Any thoughts or recommendations?
Thanks, in advance

[mkrubsack]

Have you tried MKVToolNix - GUI ? It joins MKV's and does a lot more.

[Quade]

If you have PAR files and Newsbin has Autopar enabled, they should combine after download. How about PMing me an example.

If they're split AFTER unrar, that's a different story.