Excel System for Customer & Sales Management

I need an Excel system to manage my customer and sales data effectively. The system should automate reports and provide a user-friendly, form-based interface for data entry and updates.

Key Features:
- Duplicate Prevention: The system should automatically identify and prevent duplicate entries.
- Automated Discount Calculations: The system should calculate discounts automatically based on predefined rules.
- Customer Demographics Reports: The system should generate reports based on customer demographics, focusing on age, gender, and nationality.
- Sales Trends Reports: The system should track and report on sales trends over time.
- Purchase History Tracking: The system should keep track of each customer's purchase history and calculate their loyalty.
- User-Friendly Interface: A form-based interface is preferred for ease of data entry.

Ideal Candidates:
- Proficient in Excel with experience in data management.
- Able to create automated reports.
- Skilled in designing user-friendly interfaces within Excel.
- Familiar with customer demographic tracking.
- Experienced in developing systems for sales data management.