There is no way to do what you want without doing some workaround. But I do agree that being able to set an initial starting frame would be very handy.

I have to say that either you have a fast computer or are very patience using that many frames for a cloth simulation :D You have to remember that (Frames / FPS = seconds) So using 200 frames for the cloth to settle is almost 7 seconds at 30 FPS, anyway just wanted to let you know, in case you weren't sure how to calculate it, but that might be what you need.

But to make it start at frame 200, you have to do the following.

1. Simulate the first 200 frames.
2. When its done, export the cloth as OBJ at frame 200 (Single frame)
3. Make sure that your character is fully keyed at frame 200 and shift the frames so the frames at 200 is now on frame 1 so its the new start position.
4. Import the cloth you exported in step 2 and copy the material from the old one to the imported one, and delete the old cloth.
5. Setup the cloth simulation again using the imported cloth.

As far as I know its the only way to do it.