Column Limits

I work at a dental office and we're trying to build a template for insurance limits and percentages. 

Is there any way to select a column and place a limit on it?

For example, say we have an insurance limit of $1500, if we had a column that formulated the covered percentage into a dollar amount, could the column tell once we hit the $1500 limit and start placing zeros in rather than still formatting the covered percentage? Or at least have it alert some how (example with a colour or different font) once that limit has been reached?