I'm not a SAP user but from memory I believe it is a relational database where data can be extracted using any normal ODBC or similar db connectivity method. In these circumstances I would recommend use of the MS Query tool in Excel where you create a query against the database and once the data is refreshed then have the
VB analyse the data in some shape of form.
SAP say in their website they have a relationship with SAPDB.org, they say it is an environment where you can connect to SAP using ODBC or similar methods, have you had a look, unfortunately due to firewall restrictions I cant see this site.
Have a go.
Matthew