Oracle SOA: How to surround data around fields in file adapter

I was working on one of the usecase in which we need to surround single quote(') around the fields in output file during write operation in file adapter. For example:

Input:

<QuoteFileInput>

    <QuoteFile>

        <F1>A<F1>

        <F2>B<F2>

        <F3>C<F3>

        <F4>D<F4>

    <QuoteFile>

<QuoteFile>

        <F1>E<F1>

        <F2>F<F2>

        <F3>G<F3>

        <F4>H<F4>

    <QuoteFile>

<QuoteFileInput>

Output:

Well the main logic for this is in the nxsd schema file that file adapter creates. I created a simple soa application, and the composite and bpel looks like below

In the transformation, I simply mapped the input parameter of request to file adapter input parameter.

here is my nxsd schema file:

you can download the soa project from here click here