Thank you for your reply.
I've been searching a lot, and I've come across many different options such as Arduino and way more.
The problem is that I do not have very much time left, and that, for example Arduino, isn't shipped to where I live (well, at least the parts I need are excluded).
All that led to more searching, which brought me to
http://www.secure.ws/2010/03/09/cont...omputer-for-0/, which told me I could control it simply with my sound card, a 3.5mm cable and a remote (with a 3.5mm input). And, since I've got all three of those, and since the remote does respond to being plugged into my computer via the 3.5mm cable, I got some hope back.
What gave me more hope, is that the PPM signal seems rather easy, but as I have no idea how to program stuff for my sound card in Java (with specific amplitudes etc), I came here, hoping that someone with that knowledge could possibly help me out.
If anyone would be able to provide me with a better solution, I'll be more than happy, but I really am short on time.