Hello
My situation was somewhat dissimilar. Here is what worked.
Private Sub CommandButtonTranslate_Click()
Dim pointcoords(0 To 2) As Double
'419.984252968843,235.684028561105,61.59
pointcoords(0) = 419.984252968843
pointcoords(1) = 235.684028561105
pointcoords(2) = 61.59
Dim point_translated As Variant
Dim pointUCS As Variant
pointUCS = ThisDrawing.Utility.TranslateCoordinates(pointcoords, acWorld, acUCS, False)
' Display the coordinates of the point
MsgBox "The point has the following coordinates:" & vbCrLf & _
"WCS: " & pointcoords(0) & ", " & pointcoords(1) & ", " & pointcoords(2) & vbCrLf & _
"UCS: " & pointUCS(0) & ", " & pointUCS(1) & ", " & pointUCS(2), , "TranslateCoor"
End Sub
The attached file is in a UCS where the cross section is perpendicular to the line. The point is in World coordinates.
The point is the Center Point of one of the 8 arcs forming the cross section. The translated position can be checked in AutoCad and is correct.