The best way to do this is to configure the radios in a classic point to multi-point configuration, then send your data.
Base:
DH 0x00
DL 0xFFFF
Remote (s)
DL = SL of base
DH = SH of base
Test this by sending data back and forth and moving nodes till they are out of range. Than move back till it is in range and add one as a router at that location. Then keep going farther out.
The configuration is the same but the modules are different. A Mesh module will figure out how to get the data from the Sending unit to the receiving unit on their own where as the Non mesh modules required the sending unit to be in range of the receiving unit.