IMHO you'd do better to put the images & captions into floating tables, so you can ensure they always move together, using something like:
Sub AddImageCaptionTables()
Dim iShp As InlineShape, Rng As Range, Tbl As Table
Dim i As Long, PicWdth As Single, PicHght As Single, VPos As Single
Dim HPos As Single, VRel As Long, HRel As Long, BShp As Boolean
With ActiveDocument
For i = 1 To .InlineShapes.Count
If .InlineShapes(i).Range.Information(wdWithInTable) = False Then
PicWdth = .InlineShapes(i).Width
Set Rng = .InlineShapes(i).Range
With Rng
If .Characters.Last.Next.Text = vbCr Then .Characters.Last.Next.Text = vbNullString
PicWdth = .InlineShapes(1).Width
PicHght = .InlineShapes(1).Height
.InlineShapes(1).Range.Cut
End With
BShp = False: VRel = 0: HRel = 0: VPos = 0: HPos = 0
Call MakeImageTable(Rng, PicWdth, PicHght, BShp, VRel, HRel, VPos, HPos)
End If
Next
While .Shapes.Count > 0
BShp = True
With .Shapes(1)
PicWdth = .Width
PicHght = .Height
VRel = .RelativeVerticalPosition
HRel = .RelativeHorizontalPosition
VPos = .Top
HPos = .Left
Set iShp = .ConvertToInlineShape
End With
With iShp
Set Rng = .Range
.Range.Cut
End With
Call MakeImageTable(Rng, PicWdth, PicHght, BShp, VRel, HRel, VPos, HPos)
Wend
End With
End Sub
Sub MakeImageTable(Rng As Range, PicWdth As Single, PicHght As Single, BShp As Boolean, _
VRel As Long, HRel As Long, VPos As Single, HPos As Single)
Dim Tbl As Table
'Create & format the table
Set Tbl = Rng.Tables.Add(Range:=Rng, Numrows:=2, NumColumns:=1)
With Tbl
.Borders.Enable = True
.Columns.Width = PicWdth
.TopPadding = 0
.BottomPadding = 0
.LeftPadding = 0
.RightPadding = 0
.Spacing = 0
.Rows(1).HeightRule = wdRowHeightExactly
.Rows(1).Height = PicHght
With .Rows
.LeftIndent = 0
If BShp = True Then
.WrapAroundText = True
.HorizontalPosition = HPos
.RelativeHorizontalPosition = HRel
.VerticalPosition = VPos
.RelativeVerticalPosition = VRel
.AllowOverlap = False
End If
End With
With .Cell(1, 1).Range
With .ParagraphFormat
.SpaceBefore = 0
.SpaceAfter = 0
.LeftIndent = 0
.RightIndent = 0
.FirstLineIndent = 0
.KeepWithNext = True
End With
.Paste
End With
With .Cell(2, 1).Range
.Style = "Caption"
.End = .End - 1
.InsertAfter vbCr
.InsertCaption Label:="Figure", TitleAutoText:=" ", Title:="", _
Position:=wdCaptionPositionBelow, ExcludeLabel:=0
.Paragraphs.First.Range.Characters.Last.Text = vbNullString
.Borders(wdBorderLeft).LineStyle = wdLineStyleNone
.Borders(wdBorderRight).LineStyle = wdLineStyleNone
.Borders(wdBorderTop).LineStyle = wdLineStyleNone
End With
End With
End Sub
The above code embeds all Shapes & InlineShapes in a document in tables as InlineShapes with a row for Captions. Whatever positioning applied to the original Shape object will apply to the table also. This arrangement has the advantage that captions in floating tables will show up in a Table of Figures, whereas captions in textboxes don't.
To have the caption row appear above the image, instead of below, change the Rows(1) references to Rows(2), change the Cell(1, 1) references to Cell(2, 1) and change the change the Cell(2, 1) references to Cell(1, 1).
To work with just the selected image (or multiple images in a selected range), change:
With ActiveDocument
to:
With Selection
and change:
While .Shapes.Count > 0
With .Shapes(1)
to:
While .ShapeRange.Count > 0
With .ShapeRange(1)
I haven't included code for the user to type in the caption while the code is running. That can be done post-reformatting and would be too error-prone (IMHO) if the code is processing multiple images.