incremental build

Question

33.0.123
loading "apple\folder1\folder2"
loading "bat\folder3\folder4"
unloaded "cat\fold5\fold6"

33.build.002
loading "apple\folder1\folder2"
loading "bat\folder3\folder4"
unloaded "cat\fold5\fold6"
 
33.0.122
loading "apple\folder1\folder2"
loading "bat\folder3\folder4"
unloaded "cat\fold5\fold6"
 
33.0.121
loading "apple\folder1\folder2"
loading "bat\folder3\folder4"
unloaded "cat\fold5\fold6"

Hi
i have a changehistory file like above shown,if i want to do incremental build ,i want to select build which is at first and i should discard old build history.
in the above history i had shown two products building one is 33.0.123 and 33.build.002 .daily i ll build 33.0  build and once in a week i ll build 33.build.
so i want discard 33.build and i want to select only between 33.0.123 and 33.0.122.