http://developer.valvesoftware.com/wiki/%24basetexture
Additional parameters
$basetexturetransform <matrix>
Transforms the texture before use in the material. Requires DirectX 9.
The default position is "center .5 .5 scale 1 1 rotate 0 translate 0 0".
center defines the point of rotation. Only useful if rotate is being used.
scale fits the texture into the material the given number of times. '2 1' is a 50% scale in the X axis.
rotate rotates the texture anti-clockwise. Accepts any number, including negatives.
translate shifts the texture by the given number of heights/widths. '.5' will shift it half-way.
Note: All values must be included!
$basetextureoffset <normal>
To do: DX8 version of translate?
$basetexturescale <normal>
To do: DX8 version of scale?
I think that might just do it?