Conditional Formatting Help.

[Bloodcurdled]

In column B I have a drop down list of exercises. On it's selection, I want to apply a highest value condition to the weight lifted for this exercise - columns C, G, K, O, S.

On the sheet entitled "Arms" I have only set conditional formatting by selecting the individual cells. This works fine, but requires me to keep updating the formula each time I input more data.
Ideally, I would like a formula whereby it recognises the value selected with the drop down lists and applies it to the appropriate cells denoting the weight lifted.

Forgive me if I'm being particularly dumb with this, I've only been using excel for a couple of weeks and discovered the uses of conditional formatting a couple of days ago.