I want my ant script Implement a function

hello everybody i am using ant in my project ,and i found it is difficult to copy files to different directories at one time ,but sometimes i must excute an operation like making patch to current webapps:

1. i have two dirs A and B, then i have some *.class patch files in dir A;
2. next i unzip war file of current version webapp into dir B;
3. a file named “change.list” was placed in dir A ,*.class files' names and address in the app‘s directory are described in following fomate:

CommFlowCancelListenerII.class,com/lnsoft/ess/common/
CommonOperateII.class,com/lnsoft/ess/common/

4. i want ant script read change.list file then copy those *.class files from dir A to dir B with the right address described in the change.list file so my

5. i rezip dir B to a .war file, at last this war package could be updated automatically when i run my ant script.

i have tried it for several days but i still have no result,any one can help me？ just give me some advise, please....