How to convert .msp file of NIST peptide spectral library to mzxml file?

Question

[sangeetharamachandran.25]

I have downloaded NIST peptide spectral library from NIST database(http://chemdata.nist.gov/dokuwiki/doku.php?id=peptidew:lib:human20140529) which is in .msp format. I want to convert it to .mzxml /.txt/csv file in order to read the file in MATLAB. 

Is there any free tool for the conversion? I tried to use proteowizard but it doesn't recognize .msp file

How to convert .msp file of NIST peptide spectral library to mzxml file? -