Technically brightness in the video options should work for both menu and in-game. At least it does on my last three GFX cards, which are quite a bit newer than yours though (Radeon Mobility 9700, Geforce Go 7900GTX, Geforce 8800M GTX). If my oldest laptop hadn't had a GFX card brakedown about 4 years ago I could even tell you what it would look like on a Geforce Go 440, but I'm pretty sure the brightness worked for both menu and in-game there too - but then my newest desktop has a Geforce 2MX and it seemed to work for both too - so unless the Geforce 4 Ti 4200 is the odd one out I'd suppose it should work there too.
What mode are you using: OpenGL, DirectX or SW? I personally prefer OpenGL and it always seemed to work fine for me - just be sure to use Chris custom OpenGL drivers (a search here or on Google should provide a link to them).