Try this:
@echo off
pushd "c:\source folder"
setlocal enabledelayedexpansion
for %%a in (*.rc) do (
set "name=%%a"
robocopy "%cd%" "%%a" "D:\target directory\!name:~0,8!"
)
popd
Answers to your questions are:
pushd "drive:\path"
makes the location the current working directory.
popd
restores the last working directory
setlocal enabledelayedexpansion
allows you to change and use variables within a loop, using the !variable! syntax.
If your 2000 files are in a single folder then it should work - but test it on some sample files first so that you can see how it will work.