Passing an html parameter to an embedded form

Passing an html parameter to an embedded form

I have an embedded form to which I want to pass a html parameter.

A page "test.html" includes

<iframe height='500px' width='100%' name='zoho-Student_Web' frameborder='0' allowTransparency='true' scrolling='auto' src='https://creator.zoho.com/<user>/<app>/form-embed/Student_Web/Arg1=xxx'</iframe>

I would like to call test.html&Arg=<string> and pass the value of Arg to the embedded form. In other words substituting xxx with the dynamic value passed to the html page.

I've tried all sorts of options but can't figure it out.

Help would be appreciated.

Cheers