Want to redirect the Perl stdout and stderr

Greetings,

I have a command line Perl application.
I am embedding that Perl application into a GUI application.

I have stdout redirect using

tie *SIMOUT, "MyStdOutPackage";

Sometimes I have an issue when starting up the .pl file since I am 
modifying it for this usage.

I want to redirect Perl's stdio before I call perl_parse() using the 
PerlApi.

I found PerlIO_define_layer() which takes PerlIO_funcs pointer.
So this is the only thing I found that comes close.
However I don't see the PerlIO_funcs structure defined anywhere so I 
cannot provide my own implementation.

I am stumped. Is this even possible?

Thanks,
J.R. Heisey