Nope. You can not do that I am assuming you want it only a couple of keywords to have a higher cpc. Just raise your adgroup cpc then all the keywords that you wanted to remain at the default adgroup cpc, place an **dollar amount (without a dollar sign) by every keyword that you don't want at a higher cpc.
seostew - I disagree. Your keyword max. cpc will override the ad group max. cpc, regardless of whether it is higher or lower. Google: "Keyword-level maximum CPCs always override ad group-level maximum CPCs." https://adwords.google.com/support/bin/answer.py?answer=46573&topic=10264
I disagree as well, Keyword CPC does override the ad group max cpc. Furthermore, anything set on the keyword level takes precedence, this includes destination URLs. You cannot have your bids above your Daily Budget. I think thats where the confusion is.
Just thick the keywords you want to change CPC for and press "edit keyword settings". Put your price (for example 0.24) and save. The rest of the keywords will remain at the default Adgroup CPC that you set when creating the Ad. I assume this is the answer you are looking for or Am I the one who is missing the point? lol
using the standalone Adwords Editor (Application) you can do this for all your keywords at once i believe (should you want to)