Bad IPs & using & in Excel

Everyplace you do not want your system visiting
https://zeltser.com/malicious-ip-blocklists/
https://www.dshield.org/ipsascii.html?limit=10000

Getting rid of those annoying 0's in ip addresses
http://superuser.com/questions/931682/excel-remove-leading-0s-from-ip-address

& in case you don't concatenation is:
http://www.ehow.com/how_2189391_use-excels-concatenate-function.html