Are you thinking of getting the tagnames of all the tags in 1 trend to a Text symbol? Since a trend can display multiple tags, I am just wondering are you intending to get everything or you are thinking of getting the tagname of a specific trace?
One way of getting the tagname of traces in a Trend object is using the Trend.GetTagName(traceindex) method. This will return you the full path of the tag which is \\<server>\<tagname>.
Retrieving data ...