You can programmatically send customized SMS from a Microsoft Excel sheet to your customers using Twilio's Programmable Messaging service, but users may just want to send out simple SMS without worrying about programming. You can add this functionality to an Excel spreadsheet for them with Microsoft Office Scripts. To build this solution, you need a free Twilio account, access to Microsoft Office Scripts, basic Node.js and Typescript knowledge, and Twilio account setup. The script creates a new column in the Excel sheet to send SMS from a specific number or use an alphanumeric sender ID if supported by your country. You can customize the look of the button and place it where you want. Future improvements include building a web service or using Power Automate flow for more security, scalability, and robustness.