Not easy, SAP is not native for Excel or VBE. You will need to write custom API calls in Excel to work with the application you use to read SAP data. To navagate that application you will need to use "SendKeys" functions to get that application to display data for your VBE to pull. Each time Excel communicates with the SAP server you will need to test for connection data or use a "Wait" routine to secure communication.
This may help with the VBE part but I would look in your SAP application or other SAP support for exporting to Excel utilities!