Instructions for getting a basic dll to work

I am attempting to create a dll and use it in one my scripts and I'm a bit stuck.
If you're already skilled here, show me how to do this over gchat. 

I use mingw to compile.  I can already compile basic cpp hello world into
exe and dll but when I try to run SampleDLL  that comes with MT4,
I get "unresolved function call error".

Just need a bit of tutoring here over chat.  Get me going with running
the sample and creating my own dll that runs one simple function.

I use MT4.