There is a code at JenSocial to place a notification box on members profile pages, but I'm not sure if it's one of her premium tips, or basic Ning tips.
Cool, we'll definitely check it out. Maybe this can help us achieve our end game instead of what we have been trying to do. (I'm with the same network as Angelo)
We were able to add some text to the comment box with:
document.getElementById("xg_profiles_chatterwall_post_comment").value = "some text";
Unfortunately, that puts the text directly in the rich text editor (not the HTML) function of the tinyMCE editor, so if I put (character encoded) "<a href="link">link</a>" in the "some text" it displays in the comment as "<a href="link">link</a>" instead of as "link." Not sure how to get around this :-/
Setting the delay lets the tinymce script fire first, giving access to the tinymce object and all of the associated functions :-D