it seems like you are looking for the most basic function, last().
there doesn't seem to be anything to be implemented here, it would have been a good question on the irc channel 
please see http://zabbix.org/wiki/Getting_help for support options.
Hi RichLV,
I think I didn't explain it good enough.
I'm already using last, which gives me the info that there is currently 100% packetloss.
It interests me to know if I had 100% packetloss in the past hour and how many times.
If someone calls me he has no Internet, I can look at the dashboard and have all the info at hand.
If someone's router went offline 2 times for 5 minutes in the past hour, count(1h,100) would give me 10.
I am not that much interested in those 10 minutes (in this case), but more in the 2 times it went offline.
I have a programmable RC radio (OpenTX) where this is called "edge".
I would use it like this:
packetloss.count(1h,100,,edge)=1 = went offline once in the past hour
packetloss.count(1h,100,,edge)>1 = went offline more than once in the past hour
The last triggger would be dependent on the trigger packetloss.last()=100
Having already given this example I would like to use this one as an illustration how I would like to use another feature I'm craving for a long time. I'm actually needing it for almost every trigger that's not last() (avg(), sum(), count()). In the trigger I'm showing in the dashboard I would like to give the result of the function that's leading to this trigger.
I have always cosidered this to be part of basic functionality.
Someone made a patch for this, but I can't use it (blindly) as this patch was created for an older version of Zabbix.
He named this macro
The last line I gave before would then be:
packetloss.count(1h,100,,edge)>1 = went offline {TRIGGER.FUNCTION}
times in the past hour