Text Suffix to Prefix Conversion

[EMC ROY]

Dear all,

I'm a postgraduate student in Hong Kong, studying english language. I
wanna seek help from all of you about some plain text manipulation.

I have already add part-of-speech (POS) tags with angle bracket by
software tagger, right after every word in my file, as attribute. How
could I change the tag suffix to tag prefix?

Original Sentence:       An apple for you.
Present:                     An<AT0> apple<NN1> for<PRP>
you<PNP> .<.>
Desire:                       <AT0>An <NN1>apple <PRP>for <PNP>you
<.>.

My file includes several hundred thousands of words. Manual editing is
not possible.

All suggestion are welcome!!

EMC ROY
19/04/2007