Using C++ DLLs in Node.js native Addon

I had a C++ Win32 DLL built in Release/Win32 in VS2005 and I was trying to load it into a C++ Node.js Addon using LoadLibrary. This was failing continuously. Then when I manually changed the build configuration in VS2005 to generate x64 DLL, then it worked fine. I didn't provide configuration in my binding.gyp file for addon so it was probably built in x64 by npm, as I am on 64Bit Windows.

How to provide build configurations to my addon(in binding.gyp?), if I want npm to build it build in Win32 always?

I didn't find it on Node.js addon tutorial.

This question seems to be related to following unanswered questions:

Using dll in C++ addons

DLL not being loaded within a node.js C++ addon

Thanks in advance!