Want more control? Set optional individual CPCs and destination URLs for each keyword in this ad group. [more info]
Example: keyword**0.25**http://www.yoururl.com/xyz
Thus, keyword **0.1 means the maximum CPC for this keyword is $0.1 (or any currency you're using)
It can be a pain as it seems to over-ride the group CPC, say you have the scenario where you set CPC at 5c using KEYWORD ** 0.05 then use the tool after a few days to increas inactive keywords to 10c, you now have some with ** 0.1 and some with ** 0.05. If you decide to put the group CPC up to 10c without changing the **0.05's you will not have put the CPC up, the 0.05 will apply.
As such I'd suggest checking your keyword lists after a group CPC change