The Data Warehouse API (analytics-1.4-apis/docs/data-warehouse-api at master · AdobeDocs/analytics-1.4-apis · GitHub) can be used to manage and generate data warehouse requests. However, once it arrives at its destination, it is simply a spreadsheet file and cannot be manipulated by any Analytics API at that point.
If you'd like to take the resulting spreadsheet file and do something with it, you'll want to use server-side software to parse the data warehouse file in a format Data Mart can use, then send it off. I know that there are some Adobe consultants who specialize in data connections such as this. If this is something you'd like to pursue, you can get in touch with your organization's account manager.