If its just a simple iFrame you are looking for use the built in web part already in SharePoint. If you open a SharePoint 2010 site. Click Site Actions... Edit Page... above click Insert... then click Web Part... on the left you should see 'Media
and Content' click this... now you should see what is called 'Page Viewer' web part. Click on this and click add. It will add the web part to your page. Now once its on your page. Notice in the upper right corner of this web part is
a drop down arrow. Click this drop down arros and click edit web part. On the right side of the page, you will see the config for the page viewer web part. You should be able to place the url address to your SAP app and it will display in
SharePoint.
Here is a link showing the page viewer web part.
http://office.microsoft.com/en-us/sharepoint-server-help/page-viewer-web-part-HA010024045.aspx
Good luck,
Gary
Gary Newman MCSE, MCT, CCNA MCDBA, MCAD, MCSA MCTS SharePoint 2007 Dev & Admin MCPD SharePoint 2010 Development