Hi
I found that CSS, when invoked from the command line, doesn't cope with relative path very well at all, so that it only seems to work with full paths...
If you're on linux, here is a quick script that I use to launch my opi screens:
<code>
#!/bin/bash
DIR="$PWD"
css --launcher.openFile "${DIR}/myopi.opi MACRO1=blabla" &
</code>
Hope this helps
David