downloading more headers from article mode

hi all,
i'm using "set query_read_group_cutoff -250" so that i don't have to
download a huge batch of headers all at once (which i probably do't
need) but sometimes i have unread articles that are beyond the 250
most recent articles. is it possible (maybe with a script) to download
even more aritcle headers from inside article mode?
thanks.

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Wave(TM): Endpoint Security, Q1 2013 and "remains a good choice" in the  
endpoint security space. For insight on selecting the right partner to 
tackle endpoint security challenges, access the full report. 
http://p.sf.net/sfu/symantec-dev2dev