Here's why you are most definitely on the right track of creating another coin out of one in the BlockChain itself.  IMO, this is truly brilliant because:

Leveraging something that is already created for you is not a natural engineering instinct.  But, without that concept, many ideas like creating any new coin like this are impractical.  At our company, we term it "inheritance"  where we use one structure that is dependent on other similar structures that are hundreds of times larger.  The net result is to accomplish the impossible, since that use would have required 1000 x the available resources.  (PM me and I'll give you some amazing result we've obtained in our own software designs). 

There are many needed applications for something nearly identical to Bitcoin, but which is not a BitCoin.  Yet, without a huge infrastructure to validate the transactions, any new cybercoin, even if it were identical to Bitcoin would be worthless.  Most of us have considered that almost all the miners' value has been in creating coins.  While miners' apparent value is in creating coins, their real value is in validating transactions.  By creating a new coin OUT OF a Bitcoin you instantly obtain the computing power and services of TEN Petahashes by the end of the year that more importantly, provide the transactional security service 24 x 7.

In my case, I have several separate needs.   I need to be able to create my own type of private cybercurrency for one specific purpose.  In this instance, I need to act as my own reserve currency backed by me.   In another use, I need to be able to tag all the uses of a specific stream of Bitcoin.  But for this use-case, the value backing it will be the value of the actual Bitcoin that carries the information. Two separate uses, neither of which would be practical without creating this within Bitcoin.