extract transcripts with particular class code in Cuff/GffCompare

Question

[SKY]

I want to make a new file called class_code.gtf file[containing only transcripts and related information but for a particular class code only] from annotated.gtf [which is an output of GffCompare and containing transcripts with all class codes].

How can I do it?

Please help, I am stuck

Thank you Akash