how to read sub channel data of a disc

I know some way to read sub channel data of a disc. But I failed when I attempt to use them.

1. I use IOCTL_SCSI_READ_Q_CHANNEL.
First we use IOCTL_SCSI_SEEK_MSF to position a specified sector whose sub channel I want to read.
.....Yeah, I get the sub channel data!
But the problem is : the sector is not I wanted.

It seems that IOCTL_SCSI_SEEK_MSF cannot position the sector correctly.

2. Faild! Then I use SCSIOP_READ_CD to do it.(by IOCTL_SCSI_PASS_THROUGH_DIRECT)
I know the CDB[10] is for sub-channel. But it cannot work!
I can only read 2352 bytes. No sub-channel data.

Who knows it? Please tell me.
Thanks in advance!

It sounds like a "CD Protect Check" or "Diagnostic Tools" or "CD-R Burning".
I like the topic.
Would you give me a guide?
thx

yeah, what would you like to do with it?
You are quite right. Recently I foucs on the topic.
yeah, I think there is no way to position the specified sector correctly. But other commands with address parameters can access the right sector. almost like this,I cannot concern it fairly.

How deep do you researh it? Maybe we can talk about it!

I know a little "CD Protect" tips after hours.
But I donot know how to program.(My focus is USB Driver...)
I want to adjust laser position by my program that sends some laser/CD-R controller vendor commands.
And I want to adjust laser power by the same way.
But I consult with a professional on programming burning software.
He sayes "that's impossible",because inside released-product donot have relative commands.

I have some "CD Protect" ideas.You may like it.

1.Choose the 90-minute or longer CD-R,burn "Digital Fingerprint" outmost recording-area(maybe use OverBurn tips).Then general CD-R cannot copy ur software.

2.Modify the physical layer.You must define a special burnish.That effects to change the rate of reflection.

P.S You can use some hardwares like "IDE-520" to know other software's command format.