Custom conditional format in multi-line wrapped cells

I am trying to apply a custom formatting rule to the following type of situation:

 Column S has to be a fixed width and the text wrapped to suit.

I want to indent the description text in column S where there is a value in Col T (a formula in the cell copies a value from elsewhere and applies a rounding formula).

I understand the basic formula to use, =$S30>0, and I tried the custom format "  @" (without the ") which gives the correct indent, but only for the fist line of multi-line wrapped text.

The number of lines in the cell when wrapped can vary from 2 to 15+ in extreme cases. Is there a refinement I can use to make the indent apply to all lines?

Thanks

Leslie