How to continue to watch the `Events` from the point `geth` was closed?

Question

I have a private Ethereum network. The bootnode(main node)'s goal is to watch Events and if a new Event is generated than trigger a contract's function that I want to run. The key point is triggered contract's function should only called and run once. Please note that the bootnode(main node) does not mine and geth runs inside bootnode(main node).

• watch() should be run on geth's background so when new block is deployed latest should also point new deployed block number, since latest block number keep increases.

For example, I am running following solution on geth.

> var theDAOVotedEvent = theDAO.Voted({}, {fromBlock: 1614771, toBlock: 'latest'});
undefined
theDAOVotedEvent.watch(function(error, result){
  console.log(JSON.stringify(result));
  //call a contract's function. (this should called only one time)
});

As I understand, when a new Event is generated, watch() will be called and it will print out on geth console the following example line and call a contract's function.

{"address":"0xbb9bc244d798123fde783fcc1c72d3bb8c189413","args":{"position":false,"proposalID":"11","voter":"0xebbf5d7d649aedde2c27a8b850a2a3862595eb53"},"blockHash":"0x69be968ce90c7e910c149cc80ab1e5f2ae6bdb45f142ee0e6fa181be9d1e106e","blockNumber":1614812,"event":"Voted","logIndex":0,"transactionHash":"0x6b5cab6f7987d7283fdde051c76ace98c9f080bda6dbdf720689fc0c3958005b","transactionIndex":2}
...

[Q] For example the bootnode (main node) restarted and geth closed and re-opened after 5 minutes. At this point, while geth was closed, assume new 20 blocks and 50 new Events are generated. When I re-start geth inside the bootnode's (main node), how could I continue to watch the Events from the block number that bootnode's (main node) was closed?

This approach is similar to use a pipe ("Whatever bytes are sent into the input of the pipe can be read from the other end of the pipe."). For example, when geth is shut down, Events should queued in pipe and when geth is alive again it should continue reading Events from the pipe.

I have come up with the following solution, but since synchronisation is done right after geth is re-open I was not able to run the following code piece before the synchronisation started.

//I think watch() should start from the latest retrieved block's number on bootnode (main node). 

latestWatched        = eth.blockNumber;     
var theDAOVotedEvent = theDAO.Voted({}, {fromBlock: latestWatched, toBlock: 'latest'});

theDAOVotedEvent.watch(function(error, result){
   console.log(JSON.stringify(result));
   //call a contract's function. (this should called only one time)
});

Thank you for your valuable time and help.