As you may know, Fireworks is a screen graphics tool and such text layout work is more appropriately done in Illustrator or InDesign. Although this is not a simple task in Fireworks, you could achieve this by drawing custom paths that snap to the grid and attach your text in the path(s). See the below excerpt from the Adobe Help document.
Adobe Fireworks * Format and edit text
Attaching text to a path
As an alternative to rectangular text blocks, you can draw a path and attach text to it. The text flows along the shape of the path. Both the text and the path are editable.
A path to which you attach text temporarily loses its stroke, fill, and filter attributes. Any stroke, fill, and filter attributes you apply subsequently are applied to the text, not the path. If you then detach the text from the path, the path regains its stroke, fill, and filter attributes.Note: Attaching text that contains hard or soft returns to a path can produce unexpected results.
When the amount of text exceeds the space inside or outside a path, an icon appears to indicate surplus text that was not accommodated. Delete the excess text, or resize the path to accommodate the surplus text. The icon disappears when all the text is accommodated.
Attach text to a path and edit it
- To attach text to the perimeter of a path, Shift-select a text object and path, and then select Text > Attach To Path.
- To place a text block inside a path, Shift-select a text object and path, and then select Text > Attach In Path.
- To detach text from a selected path, select Text > Detach From Path.
- To edit text attached to a path, double-click the text-on-a-path object with the Pointer or Subselection tool, or use the Text tool + click to select the text.
- To edit the shape of the path, use the Subselection tool to select the text-on-a-path object, and drag the subselected points to reshape the path.Note: You can also use the Bezier Pen tool to edit the path. The text automatically flows around the path as points are edited.
And here is perhaps a simpler idea. You mentioned that you knew how to do this in InDesign. Like InDesign, Illustrator also creates threaded text columns. Compatibility between Illustrator CS6 and Fireworks CS6 is pretty good. So I tried the following method and achieved satisfactory results.
I created three threaded text columns in Illustrator CC 2014 and saved the document as an Illustrator CS6 document. I was then able to open that Illustrator CS6 .ai file in Fireworks and thus successfully bring my columns of text into Fireworks. Once it was open in Fireworks I could save it as a Fireworks PNG and do whatever I liked.
Hope that helps.