I have inherited this code from someone else and I am not very good at coding at all. Is it complicated to swap out the functionality from Java to Openxls?
I am not aware which operating system you are on, but here is a couple of pointers that could get you started with rJava and eventually XLConnect:
So, first make sure you can successfully install "rJava" with install.packages after you setup some java environment. Then installing XLConnect will be very straightforward.