Hi, client.
Nice to meet you.
I read your job posting and I am very interested.
Because I have a good skill in windows programming.
I've already finished a lot of projects like yours.
And you said you don't have source code of your current tool.
Ok, don't worry about it, If you want, I can reverse that tool, also.
I have a plenty experience of reverse engineering. - it means that I've reversed a lot of executable files.
So please give me a chance to work for you.
I will do my best.
Thanks.