You can add the following code to the code which you had developed for
workflow

(Add the following line after all the necessary steps done for your
workflow(Moving))

Page.RegisterStartupScript("Sc1","<script
language=javascript>document.location.reload();</script>");

But can we attach the code to dll which we have linked to Document
Library.

We have to implemented through document  library. We are moving  file from
one library  to other on some events mostly update through advanced dll
option available in document library.

But document library display  (moved) file  in listing, which disappear
when we refresh  page manually.