Thank you for the kind words.
As for your problem about opening RAR archives that are in use could you provide a bit more information? Are you speaking about a single RAR archive or a multi-volume archive? Also what failure message do you get from my plugin (it should say fhRAR on the title bar)?
@pdavit
*click* from me as well

@taohe
Thanks to you for your kind words as well.
In regards to your question about extracting only part of a large file contained in a multi-volume set I am afraid that there is no way to do that at this time. Since the source is available for UnRAR I may eventually be able to dispense with having to use the UnRAR.dll file alltogether and then things might be different.