Copying data from one workbook to another based on condition

[AndyE]

The following code works for copying data from one sheet to another in a workbook.

I can't seem to alter it to allow the data to be copied from one workbook to another.

Can someone please help me out?

The active workbook is called "TotalAnimals"
The target workbook is called "Pets"

Dim sGROUP As String, rMyRng As Range, wBase As Worksheet, rTemp As Range, rPaste As Range
    sGROUP = "dogs"
    Set wBase = ActiveSheet
    Set rMyRng = Range("1:1")
    Sheets.Add , wBase
    ActiveSheet.Name = "TargetSheet"
        
    Set rPaste = Range("D1")
    Application.ScreenUpdating = False
    Do
    Set rMyRng = rMyRng.Find(sGROUP, rMyRng.Cells(1), , xlPart, xlByColumns, xlNext)
    If Not rTemp Is Nothing Then If rMyRng.Address = rTemp.Address Then Exit Do
    rMyRng.MergeArea.EntireColumn.Copy rPaste
    Set rTemp = rMyRng
    Set rPaste = Cells(1, Columns.Count).End(xlToLeft).Offset(, 1)
    Set rMyRng = wBase.Range(rMyRng, wBase.Cells(1, Columns.Count))
    Loop
    Rows("1:1").RowHeight = 15
    ActiveSheet.UsedRange.Columns.AutoFit
    Application.ScreenUpdating = True

[AndyE]

Ok so I've made some changes to this

Dim sGROUP As String, rMyRng As Range, wBase As Worksheet, _
    rTemp As Range, rPaste As Range
    sGROUP = "dogs"
    Set wBase = ActiveSheet
    Set rMyRng = Range("1:1")
       
    Set rPaste = Workbooks("Pets").Sheets("Sheet1").Range("D1")
    Application.ScreenUpdating = False
    Do
    Set rMyRng = rMyRng.Find(sGROUP, rMyRng.Cells(1), , xlPart, _
    xlByColumns, xlNext)
    If Not rTemp Is Nothing Then If rMyRng.Address = rTemp.Address Then Exit Do
    rMyRng.MergeArea.EntireColumn.Copy rPaste
    Set rTemp = rMyRng
    Set rPaste = Cells(1, Columns.Count).End(xlToLeft).Offset(, 1)
    Set rMyRng = wBase.Range(rMyRng, wBase.Cells(1, Columns.Count))
    Loop
    Rows("1:1").RowHeight = 15
    ActiveSheet.UsedRange.Columns.AutoFit
    Application.ScreenUpdating = True

But I'm getting Run Time Error '91' message
Object variable or With block variable not set -> relating to the rMyRng.MergeArea line

What's this all about?

[AndyE]

Does anyone know why this isn't working?