Is it possible to to transfer to a CSU for a semester/year and then tag or transfer to a UC? So from CCC=>CSU=>UC.
No. See below for the TAG requirements:
Who can file a TAG?
Only students transferring directly from a California community college (CCC) are considered for a TAG, including international students (those with a visa).
A CCC transfer student is one who has completed at least 30 semester (45 quarter) UC-transferable units at one or more California community colleges. The last college the student attended in a regular session (fall/spring or fall/winter/spring) before admission to a UC campus must be a California community college.
http://admission.universityofcalifornia.edu/counselors/files/tag-matrix.pdf