scanning environments

The Icon Book mentions scanning environments, but doesn't say how to use 
them.

I'm trying to modify R. J. Alexander's chkhtml.icn to clean up redundant
tags in .html files.

In the CheckHTML procedure, he does

    Line ? {
       while tab(upto(scanChars)) do {
          case c := move (1) of {
             "<": ProcessTag(f) | break
             ...
          }
       }
    }

and in ProcessTag, in the same scan environment,

    tag := ""
    ...
    until tag ||:= tab(find(">")) do {
       ...

putting the contents of the HTNL tag into the variable tag.
Then starts a new scanning environment,

    tag ? {
       ...
       # how do I access the "outer" scanning environment vars here?
       ...
    }

Is there a way I can modify the &subject and &pos of the Line ? 
environment while I'm in the tag ? environment?

Thanks in advance...

Tom Crone		crone@[EMAIL PROTECTED]