It is entirely possible to pass coordinates of a polyline to a google map, however there are many considerations.
First your polyline coordinates must be UTM (i.e. longitude and latitude).
Next, you must have a javascript embedded in your map webbrowser to pass your points.
Finally you have to construct your polyline from the points using the Google API and set it to your map.
There are a few caveats ... a webbrowser control will allow you to invoke a script (remember Javascript is case sensitive), but it will only allow you to pass a single variable. The good news is that variable must be an array of each of the required parameters of your javascript function.
Consider that you have a single marker to display, you might merely need to pass one geocoded point (-112.53412,84.84533) so your javascript function can accept 2 variables, one for longitude and one for latitude, however, if you need to pass an unknown number of verticies, your javascript function will not accept more than it was defined to handle. To resolve this, use a delimited string as the points array then pass the delimiter to your javascript function.
'This is our argument array
Dim Args(1) As String
'Build our list of points, X & Y coords (i.e. Lon/Lat)
For N = 0 to polypoints.count - 1
Args(0) = Args(0) & polypoints(N).X & "," & polypoints(N).Y
Next
'Pass our delimiter
Args(1) = ","
'Call the script
WebBrowser1.document.InvokeScript("MakePoly",Args)
function MakePoly(points, delimiter){
//you need to unpack your points using the delimiter
//and create an array of GLatLng for API V2 or LatLng for API V3
//polyline building code goes here
}
Before I catch heat, I haven't used VBA for some time, so the example may contain errors .. specifically with the AutoCAD objects ... I can't believe how fast I forget these things ...
Incidently, you can also return the value of the function as a com object to your calling function, but there is no documentation on how to interact with it, although I have made some progress, it is hit and miss for the most part, although strings and markers return nicely and are relatively easy to interact with and manipulate.
Good luck!