is there any chance that someone can change the software program that restricts the supply of Bitcoins to mine more coins.
Changing the block-generation reward to allow more than an asymptotic limit of 21 million coins would require a hard fork. It would be a contentious hard fork, because many people strongly believe that the original plan should not be changed to dilute existing coins.
Lets say as some people predict on a future date a Bitcoin hits USD $1,000,000.
Then the smallest unit of bitcoin (1 satoshi) would be worth $0.01. It is possible to hard-fork Bitcoin to allow further subdivisions; this would be far less controversial than increasing the maximum coin supply.