Running Rstudio from independent USB flash drive

I have installed RStudio, mikTex, and PANDOC in folders
on a flash drive on any computer running Windows 7.
Question: How can I get RStudio to find pdflatex.exe and use
PANDOCDto produce pdf and WORD files
on any computer running Windows?

One way is to to modify the computer PATH.
I hope there is way to get RStudio to find
pdflatex.exe and PANDOC on the flash drive
without going to the PATH.

Thank you for your consideration.
Giles

  1. For pandoc
  1. For pdflatex

HTH