hi,

see b.com (//b.com) general and b.com (//b.com) with specialization of company secretariat are two different course. however migration is generally possible if the two colleges affiliated  under same university and availability of the subject.  however since you want to change the stream it may not possible and you have to again take admission in first year.

however it  would be best to consult with college admission controlling authority to get the details of admission possibility.