index of list of lists

[Daniel NL]

yes, there's a thread with the same title, but I believe mine is more 
appropriate title.
so, as much as I search on the web, read manuals, tutorials, mail-lists 
(including this one) I cannot figure it out how to search a string in a 
list of lists.
like this one:

someList = [['somestring', 1, 2], ['oneother', 2, 4]]

I want to search "somestring" in someList which is in practice a list 
of aprox. 200 lists. (hey, I'm a newbie python programmer, don't judge 
me).
is the list.index the wrong approach?
should I use numpy, numarray, something else?
can anyone, be kind and help me with this?