Publisher: Find and replace multiple font sizes by percent

[jamfull]

Is there a way to change all the different font sizes across all pages by percent/multiplier? eg. Change all the type set in Arial by 78%
I tried using find and replace, but the format function only allows a fixed point size. I'd like to use a percentage or multiplier (eg. 78% or *0.78)
I use percentages/multipliers all the time for individual instances in the character panel, but here I want to make all the type smaller but in proportion to each other. There are just too many different sizes and pages to adjust all of them individually. 

Is there a regular expression I could use that searches the formatting?
something like: Font size:.*?
and then replace with something like: $&*0.78

Or is there a way to enter the format information into the replace box manually instead of the dropdown menus? 
eg. Instead of replacing the format with "Font: Arial; Font weight: Normal; Italic: Off; Font size: 12pt" manually type in "Font: Arial; Font weight: Normal; Italic: Off; Font size: 78%"

So far using expressions I've only managed to search the actual text, not the underlying format information. Is there a list of the Publisher specific tags I could be using in expressions, or do regular expressions only search the text?

[sfriedberg]

There are occasions where I would find this handy, myself.  However, if you are using text styles consistently in a structured document, it's usually not too hard to change the style definitions.  I seldom have more than 4 or 5 active font sizes for titles, headings and body text, some character styles perhaps with font sizes to tune subscripts and superscripts, and then usually 1 or 2 font sizes for footnotes, marks and similar.  I have lots more styles than that, but they don't all involve size changes; most of them inherit the font size of the style they are based on.

On the other hand, if you are using Artistic text to make some kind of word jazz text salad, I can see where you'd have many, many more sizes in play.

But yes, it would be nice if you could define font styles with a size that's relative to the base style size, instead of an absolute size.  Supporting either multiplicative (75%) or additive (-3pt) relative sizes would be convenient.

[jamfull]

Yes additive would be nice in other cases as well. Non-proportional, but I can see the uses for it. 

This is for a document I've imported from pdf and there are no text styles. I am changing all the fonts, loosening the tracking on some, tightening it on others, but want the leading and layout to remain basically the same. There are multiple sizes used throughout many pages. It is not a uniform design throughout the document, each page has it's own set of sizes.