Humbertogo, you need to calculate that point. The example below uses polarpoint.
Sub dbase()
Dim DAl As AcadDimAligned
Dim Zero(2) As Double
Dim Pt(2) As Double
Dim Tp(2) As Double
Dim PolarPt
Dim Offset As Double
Dim i As Integer
Dim dAng As Double
Dim util As AcadUtility
Set util = ThisDrawing.Utility
Offset = 0.45
For i = 1 To 5
Pt(0) = i: Pt(1) = i
dAng = util.AngleFromXAxis(Zero, Pt)
Tp(0) = Pt(0) * 0.5: Tp(1) = Pt(1) * 0.5
PolarPt = util.PolarPoint(Tp, dAng + PI * 0.5, Offset)
Set DAl = ThisDrawing.ModelSpace.AddDimAligned(Zero, Pt, PolarPt)
Offset = Offset + 0.45
Next
End Sub
You are still going to have to work out when you add the 90 deg or subtract it depending on the angle