[SOLVED] How do I convert an XML RSA key to a PEM file?

I have two XML files, structured as follows:

My Key

<RSAKeyValue>
  <Modulus> ... </Modulus>
  <Exponent> ... </Exponent>
  <P> ... </P>
  <Q> ... </Q>
  <DP> ... </DP>
  <DQ> ... </DQ>
  <InverseQ> ... </InverseQ>
  <D> ... </D>
</RSAKeyValue>

A Public Key

<RSAKeyValue>
   <Modulus> ... </Modulus>
   <Exponent> ... </Exponent>
</RSAKeyValue>

I am using the xmlseclibs library by Robert Richards which requires a .PEM representation of the key in order to encrypt and decrypt things.

As an encryption novice, I'm not sure where to begin, and a cursory Google search did not reveal anything particularly obvious...

Thanks!