There isn't a specific converter that I konw of.
However using the GDB tools on this page you may be able to get them into Access and up onto the H/PC that way.
http://www.hp200lx.net/super3.html
There is also MS Outlook <-> HPLX converter here:
http://www.hplx.net/super5.html (3/4 of the way down
); expect the file link isn't working