Call history export application…
This is still a very simple application but it might prove useful for some: CallHistory export will allow you to export to a tab-delimited text file your call log.
As the author describes, this could be useful for statistics purposes, call analysis, etc.
He also refers which is is the key where you can change the maximum call log length:
HKEY_CURRENT_USER/ControlPanel/Phone/CallHistoryMax (DWORD)
If you want to download the free utility, or change some ideas with the author, visit accosto.com