If you were successfully able to apply conditional formatting to one single cell, the you can use format painter brush to apply the same conditional formatting to other cells in same column (or same row based on the formatting condition defined).
One thing which you need to remember while setting the formula for CF, is that
you should NOT USE a $ sign in your formula (I mean you not freeze the column nor the row in the formula). If you adhere to these, then the format painter method should definitely work.
Another method is that - You select the entire column range where you wish to apply the CF and then insert the CF formula which you wish to use without using any $ sign and using only the first row example of the column range.
Have a look at the following 2 screen-shots showing examples.
Hope this Helps.