Windows XP coder needed

I need someone who is great with windows xp to come up with the best solution and create the system / things needed to make it work. What I have is a downloaded macro program that runs through a series of mouse and keyboard commands and then repeats itself. You cant surf the internet nor even touch the mouse or keyboard or the macro will error and stop. I wish to have another macro doing the same exact thing but in order for that, I need another computer. What i need is a system that would allow me to run many macros on the same computer. The macro also interacts with an internet browser and a downloaded program aswell. My simplest way in my opinion would be to somehow allow the mouse and keyboard actions continue as I switch to another User Account on Windows XP. Im not sure if thats even possible but could someone maybe show me what would need to be done to accomplish this besides buying more computers or having to purchase an expensive computer to run virtual machines???