Hello Yusuf, and thank you for your interest in contributing to Wine!
You should add the new DLL to configure.ac instead of configure. Run `autoconf` to copy the changes from configure.ac to configure, but only commit the changes to configure.ac to Git, not the changes to configure. Send it all as one patch and only attach one patch to each email that you send to the wine-devel mailing list.
What are the names of the applications that require this DLL?
-Alex