I have success in my trial.
To compile, i need to put the .dll file in the project subdirectory (don't put in the debug subdirectory of that project subdirectory/ solution directory)
After that, copy and paste the .dll file in the debug subdirectory of the solution directory (where all the executables already built). Then the program should be able to execute without problem.
Hope it might help those with the problems.
Though still not sure how it work as so.
my guess is something with the search path sequence:
http://msdn.microsoft.com/en-us/library/7d83bc18.aspx
So still appreciate anyone who can enlighten me on this. Thanks