easy way to do itemoffset and lineoffset simultaneous

[Björnke von Gierke]

I have a list of lines which each contain a certain amount of items. I 
need to find a certain line based on the first two items it contains.
example:
...
3,18,0,0,0,0,0,0,1,0,1
3,19,1,0,0,0,0,0,0,0,0
3,20,1,0,0,0,0,0,0,0,0
4,1,1,0,0,0,0,0,0,0,0
4,2,0,0,0,0,0,0,1,0,1
4,3,1,0,0,0,0,0,0,0,0
...

I know about the line which begins with 3,18 and now I need to get all 
lines which are nearby (x/y grid).  That means I need to get the  lines 
which begin with: 2,17 2,18 2,19 3,17 3,19 4,14 4,18 4,19
I don't know how to get these lines with that information because I 
can't do itemoffset (I need lines) and I cant do lineoffset (I got 
items).
If there just where a command like : lineoffset(item 1 to 2 of the line 
to find,container to search) :-(