Hi
You can defenitely use ActiveX conrols in Silverlight-web applications.
You should know how to use it with html, then you can write the functions to run the Activex in either aspx or html page associated withSL project.
Now you can call javascript functions from the managed code.
HtmlPage.Window.Invoke("fnRecord", "paraString");
where fnRecord is the fn name and paraString is the para name.
Dont forget to mark as answer if it helped You.
Thanks and Regards
Naveen