HIPAA-Compliant Patient Data Anonymization Script

Develop a Google Apps Script that automatically anonymizes patient data in a spreadsheet while preserving critical medical research information. The script must: 1) Replace personally identifiable information with randomized identifiers, 2) Implement AES-256 encryption for sensitive columns, 3) Generate an audit log tracking all anonymization processes, and 4) Ensure HIPAA compliance with granular access controls. Include error handling for different data types and a comprehensive regex-based validation mechanism.