Take a look at what $mw->fontActual($newfont) returns:

"-family",
"MS Sans Serif",
"-size",
-11,
"-weight",
"normal",
"-slant",
"roman",
"-underline",
0,
"-overstrike",
0
[download]

You can easily write that to a file, read it back, and use it in the arguments to fontCreate or fontConfigure.