Hi meltor,
To place a module position beside the slideshow you go to the template back-end >> LAYOUTS tab, Going to edit the default layout you would see the defined block for slideshow as below
<block name=”slideshow” type=”modules” style=”raw” no-main=”1″>slideshow</block>
From here you can see that the block is generating modules from the slideshow position, to get it showing modules from one more module positions, For example the position of banner-top you can modify the above tag to this
<block name=”slideshow” type=”modules” style=”raw” no-main=”1″>slideshow,banner-top</block>
This is just for adding a module position there, to get it display the way you wish you would need to add some css rules for that module position and I think you have to do it by yourself.