Your options to program this chip using something other then the tools provided by the manufacturer are limited. IF you can get the chip prepped by someone with the proper tools, the chips data sheet (section 20) provides details on bit banging their ISP protocol, which requires a preloaded 'bootloader' on the chip. Their ICP protocol is listed as proprietary... and not documented.
In short your best bet if you need to use this chip is to purchase the tools availble from the manufacturer.
I think I have the ISP programmer, and according to the website it looks like they recommend using an application called Keil. So i'm going to give it a go and see what happens.