cdhowie stopped development a long time ago afaik.
Perhaps you can use cgminer and one of the current methods for multipool or message conman himself.
FAILOVER STRATEGIES WITH MULTIPOOL:
A number of different strategies for dealing with multipool setups are
available. Each has their advantages and disadvantages so multiple strategies
are available by user choice, as per the following list:
FAILOVER:
The default strategy is failover. This means that if you input a number of
pools, it will try to use them as a priority list, moving away from the 1st
to the 2nd, 2nd to 3rd and so on. If any of the earlier pools recover, it will
move back to the higher priority ones.
ROUND ROBIN:
This strategy only moves from one pool to the next when the current one falls
idle and makes no attempt to move otherwise.
ROTATE:
This strategy moves at user-defined intervals from one active pool to the next,
skipping pools that are idle.
LOAD BALANCE:
This strategy sends work in equal amounts to all the pools specified. If any
pool falls idle, the rest will take up the slack keeping the miner busy.
https://bitcointalk.org/index.php?topic=28402.0 Perhaps you could specify (3*100/20)% of 1 hour to A, (7*100/20)% of 1 hour to B and so on using ROTATE. If this doesnt do what you want it shouldnt be too much difficulty for him to modify the last two.
EDIT:
Sorry misread, you want to point random machines of random hashing power to the one location which then splits it. This is not possible using cgminer (as it's not a proxy) but you could run cgminer on each computer all using the same config with the above values and it would do what you want.