If anyone's interested, I got my Rio to play and change radio stations from the radio card in my server. I'm using trio, jreceiver, and win2k server. I used this version of shoutcast:
http://www.public.asu.edu/~abarber2/wa/dnas171.exe
because it has less or no buffer.
I'm using Radiator which has a command line program to change the stations.
I have this page on the server:
<%@ Language = VBScript %>
<% Option Explicit %>
<%
'Because we might be redirecting, we must use buffering.
Response.Buffer = True
%>
<HTML>
<HEAD>
<TITLE>Radio</TITLE>
</HEAD>
<BODY>
<%
dim command
dim WShShell
dim retCode
dim freq
freq = request("freq")
command = "CMD /c c:\rad\rc.exe fr" & freq
set WShShell = Server.CreateObject("WScript.Shell")
retCode = WShShell.Run(command)
Set WShShell = nothing
Response.Redirect("http://server:8000/listen.pls")

'Flush Response Buffer.
Response.Flush
%>
</BODY>
</HTML>

and some links in trio like this:
http://server/radio.asp?freq=10190
to change the station to 101.9.

Of course there's no error checking, and it's not secure, and a user must be logged on to the server, but it works for me.