Icwai

No exemption is available on the basis of any other qualification (CA) under Revised Syllabus, 2008. 

computer practical training is compulsory, GD/BC and other training after passing intermediate is also compulsory to qualify for CWA.. 
and you are eligible for intermediate if you register on or before this 5th june 2012 for december 2012 exams.. 

NOTE: CA+CS combination also does not permit you to give straight away the final CWA exams, you have to appear for intermediate exams. 

ABOUT exemption of 3 years practical training exemption, please go through this link 
just click on it u'll be redirected to a post of a well known member of CCI who posted this topic earlier :
/forum/procedure-for-practical-training-exemption-icwai--180302.asp