A: For sure, you can see this short tutorial on how to send messages to numbers via excel,

Message you can create within excel itself using variables like Birthday, Name

https://youtu.be/0MpR71urCiY?si=9qPhilIL8Aq1M7f2

Sample google sheet just to show how to create message using variables -
https://docs.google.com/spreadsheets/d/1kf3rbBTBDDJ3BrCfY7r0v9pdgSCSns09RTAalQV5jII/edit?gid=0#gid=0

If you are not good with excel/csv in terms of creating message with variables/formula. Then you can user our in-app template builder - https://wbiztool.com/template-messages/

It's available Tier 3 onwards