I am doing something similar by triggering formatting rules for e-i-c where the root element att value is equal to the child's att value, by way of counters. This should be possible (or at least probable).
Set up a couple of uninitialized Arabic counters.
Once you get each variable value, set each counter with them like this:
<att>
<fillval attname="revlevel" fillcat="enumerat" fillchar="increm">
<charsubset>
<enumerat enumid="current-rev" setvalue="2"></charsubset>
</att>
Then you should be able to test against it like this:
<att>
<specval attname="revlevel" attval="#EQ#current-rev">
<charsubset>
<neat-stuff>
</charsubset>
</att>
One odd thing I've noticed, that the documentation seemed a little misleading on (I noticed it in your example), was that I didn't need to set the attloc to #FOSI. IIRC (which I might not, it was a few years ago when I coded this), I think my rule kept failing until I removed the #FOSI, and I think this was included in one of the documentation examples, so it took me a while to get this working.
Hope that helps...
-Jason
