Word - find/replace highlighted text with shaded text AND preserve all other formatting?

I create new documents from source material that others send me, and use Word's built-in gray highlighting to indicate text in the source file that's been dealt with in the new document (equivalent to "crossing it off").

Onscreen, I can still easily read the text; the highlighting does not interfere with legibility. However, when printed, the highlighting is so dark that it interferes with legibility.

Going forward, I will use shading (not highlighting) to get a lighter gray background. In the meantime, I have several documents to be printed. Using find/replace is the obvious solution, but my experiments with it are failing.

In Word 2010 you cannot replace highlighting with shading; you can only replace highlighting with highlighting. The obvious solution to that barrier is to create a new style with shaded text.

But that solution does not work because the new style replaces all of the text formatting (indents, etc.), not just the highlighting.

I've tried variations of creating a new style with shading based on normal, based on no style, and (for example) a new style based on the custom "Text" style that is sometimes used.

Can what I want to do--replace highlighting with shading while leaving all else "as is"--be accomplished with find/replace in just one to a few steps? I.e., if it takes a few passes of find/replace, that's ok.

If this problem is beyond a find/replace capability, then how else can I accomplish it?

Note: Replacing the gray highlighting with another highlighting color is not a solution. Nor is changing the text color.