How to insert the "modified time" attribute in "date taken" attrib in batch mode

Hello,
I am using windows vista rc1.
I tried many softwares ,to insert the date modified attrbute into the
"date taken" attribute of an image file..but was not able to find
anyone of them really do the job.

Attribute magicpro is closest match for this task but its in beta
currently so the changes are not really reflected in windows(VISTA
RC1).[In win xp the date taken attribute isnt available i think..but
this is immaterial]..

If there is a way to do this in vista inbuilt then please suggest how
to do this...NOTE i know that I can do it individually...but I have
hundereds of photos so i am looking for batch mode..

And the info that is to be inserted is a variable..so for every
file..the modified time attribute is to be read and inserted into the
date taken attribute..and so the mmanual-select all and modify the
attribute from windows for all the photos wont work..

My cameraphone doesnt add this info in the date taken attribute
defaultly..so I need to do this to let a better organisation of my
photos..

the renaming feature is fine(renaming the title including the modified
timestamp,i have achieved this with the beta software,attribute magic
pro)
but i need this info to be inserted into the date taken
attribute of my photos...

In short I want this::assign,"date taken" attribute,the "modified
time"attribute,
in batch mode.

Can anyone suggest a software that does this effectively..

Thanks.