Do I need XML parser ?

Hello,
 As I am new to this XML business so I got a basic and simple question.
Here it goes...
I have one cobol data file (in ASCII format) and one cobol record description file to describe the position/length of each field of data file.

I want to generate one XML file out of that cobol data file. My question is
1) Do I need any XML parser to just generate one XML file from a data file ? Or a simple programming logic can create the XML file ?

2) While environment/programming language would be best in this scenario ?
        a) program written in cobol on Mainframe ?
        b) to transfer the datafile to a Unix m/c and the generate the XML file in C language ?
        c) to transfer the datafile to a Unix m/c and the generate the XML file using shell script ?

Any quick help would be highly appreciated !

Thanks in advance,

Regards
Rabindra Nath Saha