You are not the first person to need this. If you are able, this would be a fantastic addition/extension to the CCScaleBy or CCScaleTo actions:
CCScaleTo::Create(1.5, 45, ccp(45,45));
The default behavior is to use the anchor point, but being able to override this in an action is immensely useful.
Please fork and PR back on github if you can. I am sure there are a hundred people out there who would use this the minute it hit the framework.