Replacing a DLL

I have a windows app that calls LoadLibrary on all the DLLs
in a certain directory.  It doesn't actually call any
functions in the DLL; simply loading it causes the desired
effects to take place.  I'd like to replace one of those
DLLs with a WineLib version that calls some Linux functions.

I've compiled the WineLib dll with Winemaker, so now I have
mydll.dll.so.  It's written in C++, by the way.  How can I
replace the normal mydll.dll, such that the Windows program
will load the winelib dll when I run it with Wine?

-Steve