Is there any way to use the apple Time Capsule as a range extender?
Yes. There are two ways to do this, with one method much better than the other.
Method 1.....Locate Time Casule 2 where it will be needed to provide additional wireless signal coverage and then connect an Ethernet cable from Time Capsule 2 back to Time Capsule 1.
The upside with this method.....there is absolutely no signal speed loss through the Ethernet cable so both Time Capsules perform at maximum speed, delivering the best performance for your network. The downside....you have to run the Ethernet cable.
Method 2.....Locate Time Capsule 2 about half way between Time Capsule 1 and the general area where more wireless signal is needed, and set up Time Capsule 2 to wirelessly extend the signal from Time Capsule 1.
The upside with this method is that a wireless connection is used to allow the Time Capsule to communicate together. The downside here is that when you try to extend a network using a wireless connection, about half of the potential speed on the network will be lost, so backups, downloads, etc will be significantly slower than they are now.