Try this
Sub TextDemo()
Dim objsset As AcadSelectionSet
Dim ObjEnt As AcadEntity
Dim minExt As Variant
Dim maxExt As Variant
Dim BoxWidth As Variant
Dim BoxHeight As Variant
Dim Text As AcadText
Dim Height As Double
Dim inst(0 To 2) As Double
Dim PrecVal As Integer
Height = 4
inst(2) = 0
PrecVal = ThisDrawing.GetVariable("LUPREC")
Set objsset = ThisDrawing.PickfirstSelectionSet
objsset.Select acSelectionSetAll
'On Error Resume Next
For Each ObjEnt In objsset
If ObjEnt.Layer = "0" Then
ObjEnt.GetBoundingBox minExt, maxExt
BoxHeight = maxExt(1) - minExt(1)
BoxWidth = maxExt(0) - minExt(0)
inst(0) = (maxExt(0) - (BoxWidth / 2)) - 6
inst(1) = maxExt(1) - (BoxHeight / 2)
Set Text = ThisDrawing.ModelSpace.AddText("x", inst, Height)
Text.Alignment = acAlignmentMiddleCenter
Text.TextAlignmentPoint = inst
inst(1) = inst(1) + 5
Set Text = ThisDrawing.ModelSpace.AddText(ThisDrawing.Utility.RealToString(BoxHeight, acArchitectural, PrecVal), inst, Height)
Text.Alignment = acAlignmentMiddleCenter
Text.TextAlignmentPoint = inst
inst(1) = inst(1) - 10
Set Text = ThisDrawing.ModelSpace.AddText(ThisDrawing.Utility.RealToString(BoxWidth, acArchitectural, PrecVal), inst, Height)
Text.Alignment = acAlignmentMiddleCenter
Text.TextAlignmentPoint = inst
End If
Next
objsset.Delete
End Sub