[amibroker] how do count the number of buys in a system using explore

[nickhere]

for example
buy=(close-open)=1.00;
this produce 
around 20 buysignal

what I want when I run explore
column 0 to equal the number in the buy list
be it 1 2 ...

amd=1
bby=2
bby=3  bby came out twice
msft=4
and so on