Display setting problems with TV

[foxxy_grandpa]

I found the file you're talking about; It looks something like this
{options
{video
{resolution
{mode desktop}
}
{antialiasing "2x"}
{full_screen}
{vertical_sync}
{detail detail_medium}
{shadow cross_filter_shadowmap}
{filtering anisotropic2x}
{model_quality high}
{fx_quality high}
{bump}
{specular}
{environment}
{waterBump}
{water_reflection real}
{grass}
{bloom}
{clip_distance 1}
{gamma 1}
{brightness 1}
{contrast 1}
}
(This was taken from my PC's file, not his btw)
I'm just not sure how to enter a custom resolution. I fiddled with the line with "resolution" in it, but can't get anything to change to what i type in. Does anyone know how to set the resolution this way?