Excel Downloader: Windows Program Development

I need a Windows desktop program that can automatically log into certain login-required websites, check for new Excel files, and download them. This task should be performed every hour.

Key Features:
- Program must handle Username and Password authentication to access the websites.
- Program should be able to identify and download only Excel files.
- Program needs to operate on an hourly basis.

Ideal Skills:
- Proficiency in Windows desktop software development.
- Experience with automating web downloads.
- Knowledge of handling login-required websites.
- Expertise in programming for Excel file recognition and download.