SALioness - 8:25 pm on Oct 16, 2007 (gmt 0)

I need advice urgently. One of my client's domain names, .com, expired not so long ago. When the client contacted me and decided that he wanted to continue with the domain, I discovered that this domain was hi-jacked and registered by "software". This company specifically makes money by registering domain names and uses software to establish what domains have expired and registers them. I initially mailed him and asked for my domain, but he asked me $700 for this domain. It appears that this domain only expires now in 2008. Is this legal? Is there anything I can do to get this domain name back?