SAS AMO is a SAS 9 product
You could set up a Stored Process to call Viya if you're running both. Or, use VBA to call the SAS Viya REST APIs.
Otherwise, you'll have to wait for the office support in Viya (might be out already) that brings connectivity to Office 365. Not sure about legacy excel though.
/Allan
MacroCore library for app developers
Data Workflows, Data Contracts, Data Lineage, Drag & drop excel EUCs to SAS 9 & Viya - Data Controller
DevOps and AppDev on SAS 9 / Viya / Base SAS - SASjs