That's a pretty simple material file, and you could recreate those materials in just a few minutes. In fact it's so simple, you don't even need it, as you will want to use Corona materials anyway, instead of standard Max materials. But if you did want to recreate it, there are really only a few lines you need to care about:
'Ka' is 'constant ambient', which is the ambient colour of a standard Max material (in linear float format).
'Kd' is 'constant diffuse', which is the diffuse colour of a standard Max material (in linear float format).
'Ks' is 'constant specular', which is the specular colour of a standard Max material (in linear float format).
All you need to do is find a simple calculator to convert linear float numbers into sRGB integer numbers, there are plenty online. Takes me back to my Renderman shader writing days, where I would code shader files in a text editor.