So the following solution worked for me:
1. Uninstall your existing R and Friends setup. There are potentially quite a few components you might need to uninstall. I would suggest the correct reverse sequence i.e. RExcel, StatConnDcom, R
2. I downloaded the versions of StatConnDCOM and RExcel from
http://rcom.univie.ac.at/download.html3. Install R
4. Install StatConnDCOM
5. Install RExcel
6. The following packages were downloaded from CRAN and then installed: rscproxy and rcom
7. Then the COM components need to be registered. At the R prompt enter the following commands:
> library(rcom)
> comRegisterRegistry()
> comRegisterServer()
n.b. I think it might be worth trying step 7 with your existing installation of R, before you uninstall. Let me know if this works for you.
After doing this I was able to start the R Server from the Excel add-in menu in either forground or backgreound mode.