PERL split function

Hi... I have a question regarding the split function in PERL.

I have a very huge csv file (more than 80 million records). I need to extract a particular position(eg : 50th position) of each line from the csv file. I tried using split function. But I realized split takes a very long time.
Also it splits the entire line and puts in a array when I need just the 50th position field.

Is there any option to extract the field at a particular position in perl.
Plese help me out with this.

provide some input data please.
BR