Skimmer should be before the fuge.... What you could do is leave the skimmer in the first compartment and the return chamber in the center section and the fuge on the far end....
You would feed the fuge from the drain line from the overflow box, and what would happen is you would split that drain line into 2... Putting a ball valve on the line split from the main line feeding your fuge, so you can control the flow going to the fuge....then your fuge would overflow back towards the left into the return chamber area...Your skimmer compartment or chamber would overflow into your return compartment as well...
Might be alittle confusing, but a good site to check out would be melevsreef.com. Has alot of good information on that site, and also has constuction tips and such...