Easiest way(I think) would be to change the bit of code that reads:
#Prompt for SNMP community string
print "community: ";
chomp($community = <STDIN>);
Then launch the script with cdppoll.pl ip > nameoftextfile
I am sure that there is a better way to do this(and one day I'll get off my but and add some text output as an option)
Or if you open a filehandle to write to inside the code change the format STDOUT to format FILEHANDLE and the write to write FILEHANDLE. That should work as well.