This could be your constant current. I have placed the load in the collector in order to ease the output voltage of the OP Amp.
You need a SMPS for the 30 V. Depending on your exact application, probably the load can be placed in the emitter and derive the supply of the OP from the VCC (SMPS).
Depending on the intended variation of the current, the reference voltage can be derived from the SMPS or bypassed with additional linear voltage regulator for lower ripple.
For the SMPS for 30 V output and 200mA, I would go with Flyback, so check how power integrations implements a Flyback with those requirements.
P.D.: I guessed from your very little information that you want to drive a LED string in series with the 30 V, so that explains the 28 V voltage source which represents the large string of LEDs.