Date conversion from DD MON YY to mmddyyyy

I am new shell scripting.
Can someone please help in giving a shell script to convert from DD MON YY to mmddyyyy

Example:
Input1 :- 20 Apr 2011
Output2 should be :- 04202011

Input2 :- 09 MAR 11
Output :- 03092011

Input3 :- 30_JAN_11
Output :- 01302011

Need help in writing shell script in coverting all the 3 above examples.

Thanks in advance for all your help.

Sorry, but i have to ask: is this homework?

Anyways, this thread doesn't have anything AIX-related so i move it over to "Shell Programming and Scripting".

-push-

bakunin