Conditional Formatting Based on Specific Word in Different column in Same Row

How can I conditionally format (highlight) some cells in column K based on the values in column C of the same row?

For Instance:

I export a large report into excel from a worktool at work. I have many columns but I want to draw attention to cells in column K based on the text "###" on the same row in column C. (there are many different codes that populate besides ###)

The only thing I can think of is to highlight an individual cell in column K and go to 'Use a formula to determine which cells to format" My formula is: =$C$1="###" and format the highlighting color.

This report has over 500 rows so it is not feasible to do that same process 500 times and create 500 rules.