[XSL-FO] marginal notes

All, 

I need to add marginal notes to a two column layout in XSL-FO 
(I am using Antenna House) 
And in general this works well using floats 

<fo:change-bar-begin change-bar-class="CBP-{generate-id()}" change-bar-offset="5mm"> 
<fo:float float="outside"> 

I am facing two issues now 

1. The float="outside" works well in a one column layout to put my notes in the left margin on even pages and the right margin on odd pages 
However I can't seem to figure out how to put margins on the left for the left column and on the right for the right column 

2. In my XML a set of lines make up a paragraph, the "lines" are numbered and I need the "number" in the margin 
Sometimes 2 "lines" start on the same physical line in the column and the marginal notes in the side bar are printed at the same location 
Is there a way to fix it in a way that a second float is printed below the first when both are on the same height? 
I have been playing with markers but ca,t get any pleasing result 

Thanks a lot 

Geert Bormans