Robert,
Unfortunately no, there's no querystring parameter that relates to attributes
If you have the source and feel adventurous .. :)
In the page load, where the grm2catid is processed add some code to look for attributes. Like the category id, you'll need to lookup the ID of the attribute(s) you want. Let's say you have attributes 11 and 12 that you want to create a link to.
Now, to autoselect attributes 11 and 12 via a URL, add &attrib=11;12 to the QueryString (semi-colons between attributes if you want to select more than one attribute. To show all attributes, add &attrib=ALL to the QueryString
If you're using Friendly URLs you would add /attrib/11 or /attrib/11;12 or /attrib/ALL
If Request.QueryString("attrib") <> "" Then
If Request.QueryString("attrib") = "ALL" Then
oRepositoryBusinessController.g_Attributes = ""
Else
oRepositoryBusinessController.g_Attributes = ";" & Request.QueryString("attrib") & ";"
End If
mFilter = ""
End If