[R] Update MS Windows PATH variable based on a R script

[Janko Thyson]

Dear list,

this is not directly an R question, but it is somewhat related to R 
aspects, so I hope it's okay to post it here:

I'd like to update my windows PATH based on a script routine in order to 
make sure that crucial components are contained. Much like what happens 
at the installation of Rtools (if desired). Now, can you do that from 
within R or do I need some sort of windows batch file or something like 
AutoIt script (http://www.autoitscript.com/site/autoit/)? If so, what 
would I need to put in there?

Here's what I tried in R:

unlist(strsplit(Sys.getenv("PATH"), ";"))
PATH.0 <- Sys.getenv("PATH")
PATH.1 <- paste(PATH.0, "C:\\blabla\bin")
Sys.setenv("PATH"=PATH.1)
unlist(strsplit(Sys.getenv("PATH"), ";"))

The changes seem to be reflected, but when I check my PATH the new entry 
isn't there. I guess there is no actual "feedback" to Windows system 
environment variable and that's exactly what I would like to accomplish

Thanks a lot for any advice,
Janko