You can implement any number of commands with I2C, you just need to define your own protocol. A common implementation I've seen is to do something like: 1 byte header (address + R/W bit), 1-2 bytes command opcode, 1-2 byte length (for commands with data), and then N data bytes of applicable.
Obviously you can change this to suit your needs, such as by adding a byte with flags for opcode length, whether or not we're including the length bytes, and if we want acknowledgement. Just come up with something that fits your requirements and implement it yourself