Simple Project For C++ Programmer

This project is fairly simple if you're a experienced c++ programmer. I have a exe that I need turned into a dll to be called from vb.net. Right now I call the exe through command line like this "[login to view URL] [login to view URL] result.txt". The exe executes the action and saves the result to result.exe. I have the full source code to the exe. I want to have it turned into a c++ dll so I can call from vb.net dllimport function instead of calling the exe. I want to call the dll with the filename in the argument and have it result the result, instead of writing to a file. Like I said this is a fairly simple project for a c++ programmer. I will always need a c++ programmer so this would a good start to build up a good relationship :-)