Hello my friend, I am interested in doing this project for you. I have done many such projects using C#, and if you choose me I will do it using the same language. This won't really effect you unless you plan on modifying the code yourself, but please note that it will only run in a Windows environment.
I believe I can help you with your problem, assuming the application is written in C#. It could be a minor thing or a major thing; we will have to look at the coding.
I am available on Skype throughout the day and have pretty good English, so communication shouldn't be a problem. I am also a registered freelance programmer in my country with a VAT number, if that sort of thing effects you. Hope we get to work together and thanks for reading.