How to read the AD7356 ADC with an Arduino?

Hello,

I got an Arduino Due and an AD7356 SAR-ADC. To enter the ADCs normal operation mode it is necessary to set the SPI chip select pin high after the 10th and before the 14th CLK and to get the data of both channels on one SPI data pin I have to set the CS low again.
Is it possible to count the clock signals and control the CS Pin manually with the Arduino IDE or is there any chance to read the data from th ADC?

It would also be interesting to know, how to setup a higher SPI CLK than the default 4 MHz. 12MHz should be possible with the internal RC Oscillator?!

Thanks for your help