I can't seem to insert a "floor()" into variable dice amount macro?

I am running a 3.5 game and am setting up macros for my players which are less than amazing with the rules. One player has chosen a spell which allows a variable amount of dice with a maximum, and I got that, but I can't get the function to round down without it breaking. The spell is lesser, orb of sound, which I have copy/pasted below... An orb of sonic about 2 inches across shoots from your palm at its target, dealing 1d8 points of sonic damage. You must succeed on a ranged touch attack to hit your target.  For every two caster levels beyond 1st, your orb deals an additional 1d8 points of damage: 2d8 at 3rd level, 3d8 at 5th level, 4d8 at 7th level, and the maximum of 5d8 at 9th level or higher. I wrote a macro that will calculate how many dice will be rolled, and automatically roll them, with the max of 5d8, buuuut I need it to round down. This part works fine= [[  {(  1+((@{arcanecasterlevel}-1)/2)  )d8, 5d8}kl1  ]]  }}, but its missing the floor() that will round down decimals. If I put that in, then it breaks. Here is what I need it to be= [[  {(  1+floor((@{arcanecasterlevel}-1)/2)  )d8, 5d8}kl1  ]]  }}.  I feel like this is just a syntax error, but I put in a new set pf parenthesis all over this thing and it doesn't seem to help. Any suggestions?

This is untested, but I would try replacing the outer () with [[]]. That will force it to be resolved to a number before it tries to roll any dice, since the dice roller works from the innermost to outermost with inline rolls. [[  {[[1+floor((@{arcanecasterlevel}-1)/2)]]d8, 5d8}kl1  ]] I also removed some of the spaces, in case they were an issue.

That is really fascinating. I never considered [[ ]] brackets inside of other brackets. I put it in and it works. You have leveled up my macro skill. Gosh, I wonder if this is what it feels like for the Dragoborn, when he hands gold to Faendal? I feel kind of bad for stealing it all back now. Thanks for the help, and the moral conundrum.