Windows Software Functionality Enhancement

I need a skilled developer to modify an existing Windows-based software.

Key requirements:
- Change existing functionality according to my specifications.
- Add new features as per my needs.

Ideal skills and experience:
- Proven experience in Windows software development.
- Strong understanding of software functionality modification.
- Ability to add new features seamlessly.
- Good communication to understand my requirements clearly.

Please provide examples of similar work done.