Select the cell you already have conditionally formatted.
Press Conditional Formatting and then Manage Rules. In the field 'Applies to' write the range with all your columns. OK.

The problem is the formatting of column D is dependent on the letter in cell D11, Column E is dependent on the letter in cell E11, and Column F on the letter in F11. If I just tell the conditional formatting to apply to all cells in column D,E, and F, it will base the conditional formatting of Column E and F on the letter in cell D11.

Attached Images

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