I work mostly with horizontal wells. Maybe I can shed some light on your problem.
If the tie in point is down hole and you have data above the tie in point, the only thing you can do is to enter a survey point at your uppermost depth, of inclination 0 deg in oil field terminology or -90 in LogPlot terminology and azimuth as 0, then enter the survey information for the tie in point at the correct depth. From there continue entering surveys to TD or wherever you last survey is.
If this doesn't make sense I can post an example file for you.