I guess I'm a bit confused; the CSS property used by EnhancedHTML2 accepts an expression. That expression should output a CSS class name, based on whatever logic you put into the expression. You then assign a style to that CSS class name to accomplish highlighting or whatever. You can absolutely apply a specific style name to a single cell within a row.
Is what you're doing applying "red" for all of the cells in a single *column*? You should do that using the existing code without modification… maybe I'm not getting what you're doing?