If he wants 1280x1024, then it's likely to be a 17" or larger "square" LCD, which run in the stupid ratio of 5:4, rather than 4:3 (which is what 1024x768, and most other resolutions are).
Having looked about, it appears though running Q2 in any other resolutions than those already in the game requires re-compiling the game from source, adding the resolutions you require.
Lancer, plenty of games allow for specifying of custom resolutions, to allow for future larger screens and ratios (such as widescreen). There used to be a great resource for Widescreen gaming, however it appears their domain is now just one giant advert... guess they died.