I do not think that ODS LAYOUT and ODS REGION will work with TAGSETS.EXCELXP. Tech Support could answer that one for sure.
If you switch to ODS and use an HTML-based tagset, then you MIGHT be able to open the HTML file with Excel and have the multiple tables respected. There is a tagset called HTMLPANEL, that will put HTML tables side by side -- it uses features of ODS LAYOUT and ODS REGION -- but since the result is "pure" HTML tags, then Excel MIGHT open the HTML file that you created with ODS HTMLPANEL. This tagset is not part of the installed set of tagset templates that are delivered with SAS and you would have to download it and read the documentation. I suggest getting it working so it looks good in a browser and THEN see how Excel deals with it. Generally, Excel doesn't like HTML 4 tags, so there's a chance that this will NOT work. Tech Support might know right away whether this is a good suggestion on not.
Your last choice might be to see what the TABLEEDITOR tagset does for you. It uses Javascript and HTML to create tables that can be sent to Excel. In spite of the name this is a pretty cool tagset that does MORE than just allow you to edit your tables. Again, Tech Support can help you with this tagset if you can't figure it out from the documentation.
For more information about these other tagsets, go to:
http://support.sas.com/rnd/base/ods/odsmarkup/
and follow the links for HTMLPANEL and TABLEEDITOR. To contact Tech Support, go to:
http://support.sas.com/ and on the left hand side of the page, click on the link that says: "Submit a Problem".
cynthia