adobe indesign - How can I make a hanging indent where a title is outside of a text frame?

I have a layout with two columns, and I would like the header to go outside of the text frame like this:

However this would mean the Header text hanging outside of the text frame. I could achieve this using a separate text box for the headers, like this:

However, this has a couple of major drawbacks. Firstly the headers would not flow with the text, and secondly the columns would not be split correctly below the header.

What I want is to have the header set up as a paragraph style, so that it spans columns, but hangs left of the frame:

I could "fudge it" by setting the body text to be indented, and make the columns wider to accomodate this, but that wouldn't work either as the text in the right hand column would also be indented, so the gutter would be too wide:

How can I make this work?

Answer

• Insert a hair space character before the title


• Select this character and set its tracking to -1000

If the hair space character does not appear anywhere in the text, you can create a paragraph style with a GREP applied to all hair space characters.

Add after @Lucian's comment, the same hair space character with 200% horizontal scale