Error using csvread to import massive excel file

I am using csvread to open a excel file in segments because the original file is too large to open in excel. I can open the first portion of the file with the following code:

% determine the number of data points 
datapoints = 250000;
nc = 54;

% Calculate the range of data removed frome the csv file
r1 = 4;
r2 = ((datapoints*nc)+r1);
c1 = 0;
c2 = 0;

%gather data from csv file
data1 = csvread(file,r1,c1,[r1,c1,r2,c2]);

However when I manipulate the variables to carry on to the next portion of data using the following code:

% determine the number of data points 
datapoints = 100000;
nc = 54;

% Calculate the range of data removed frome the csv file
r3 = ((datapoints*nc)+r2);
c1 = 0;
c2 = 0;

%gather data from csv file
data2 = csvread(file,r2,c1,[r2,c1,r3,c2]);

I get the following error:

??? Error using ==> dlmread at 145 Badly formed format string.

Error in ==> csvread at 54 m=dlmread(filename, ',', r, c, rng);

Error in ==> programtest2 at 51 data2 = csvread(file,r3,c1,[r3,c1,r4,c2]);

Is there a way to solve this issue? Thank you

[per isakson]

How large is the file? In your last question you mentioned 1GB. A 1GB csv-file shouldn't be a problem with Matlab. Is it pure numeric?