Heterogeneous networks (HetNets) are typified by cellular deployments with multiple types of cells of different sizes and overlapping coverage areas using a common frequency band. Especially, hotzone cells overlaid on a macrocell to cover hotspot areas are expected to prevail in HetNets, thus cost-effectively enhancing cellular capacity via spatial reuse of spectrum resource and offloading macrocells. In order to fully achieve such benefits, users need to be properly distributed/assigned to the overlaid hotzone cells such that the radio resources therein are fully utilized. To this end, we propose a new architecture called Adaptive Range Control of Hotzone Cells for Heterogeneous Networks (ARCHoN) that jointly controls the radio resource allocations and ranges of OFDMA-based hotzone cells. The use of cell ranges for distributing users in ARCHoN is advantageous in that it can be implemented within a conventional cell-selection framework without modifying user devices or an air interface. In ARCHoN, each cell allocates users radio (frequency, time and power) resources in a non-cooperative manner, deriving a sequence of allocations monotonically decreasing the entire load. For range control, two algorithms are proposed: per-cell and universal, which have a tradeoff between performance and computational complexity. The solution yielded by the combination of these radio resource and range control algorithms is analytically proven to converge to a unique fixed point. Our in-depth evaluation has shown ARCHoN to significantly improve the service quality of users; in an example simulation scenario, ARCHoN is shown to improve the signal-to-interference and noise ratios (SINRs) of users, on average, by up to 3.5 dB in downlink and 18.8 dB in uplink, over the case of the conventional handover framework.