Theres no way that FX5200 is gonna want to play that. No doubt you probably can but we're talking low settings, low resolution, no aa or anything like that of course. The FX5200 isn't even meant for gaming at all. Lacks the architecture for it and some instructions crucial for awesome gaming (check out nvidia.com for more info on that)
Doom3 was made to be playable even on some fairly low systems but I just think that 5200 will be killing you. They showed it playing on like Gf4 Ti's which are probably more powerful than that 5200