I have created a report that I will embed in Sharepoint 2007 via a webpart using a report viewer. This works well and looks rather nice, however in the report I have a text
Adding to Christine's answer, if Fields values are required, something like this can be done:
="javascript:void(window.open('https://myserver/mypath/mypage.aspx?myID=" & Fields!myID.Value & "','_blank'))"
Have you tried using javascript and window.open to open a new window in the Go To URL action of the textbox? For example:
="javascript:void(window.open('http://myserver/mypath/myasppage.html', '_blank'))"
Check out this article for more info.