Can I link a chain of airport express devices to use as wifi extenders?

Question

Hi all,
At work we have a large warehouse, office at one end, offices at the other end and warehousing in the middle (to keep things simple) .  I would like one single wifi network for the whole building so I can link up Filemaker to iPads, iPhones, Macbooks etc.  I have bought two Airport Express devices and put them at two ends of the building but they don't reach each other so I've temporarily set up two wifi networks.  I will need a 3rd, maybe even 4th Airport Express.
My question is this:
Can I form a chain of airport express devices to use as wifi repeaters from the first?  i.e. Can a repeated wifi signal be repeated again?
Or in other words... say I have 4 airport express devices (A, B, C, D) and only A is linked to the network with a cable...B repeats the signal from A. (A is out of reach of C and D).  B repeats the wifi signal from A to C...C repeats the wifi signal to D...will this work/is it possible?
Thanks!
p.s. hopefully I haven't confused you too much

Answer 1

Hi - Tesserax is right - you can't do this wirelessly but I notice that you say that you have temporarily set up two wi-fi networks - does this mean that you have access to ethernet connections - if you do and the distances aren't too long, then you can do it by placing wired base stations where their wi-fi would overlap - you would then set up each to create a wireless network with the same name, password and security type - and as long as they are on the same subnet, you would have a roaming network so that clients can move from one "zone" to the next without having to re-connect - I have 2 parallel networks using 8 Extremes and 2 Expresses connecting 3 hangars and 3 offices and it works great.