Попробуйте заменить Chr (10) ничем
Sub Test()
Dim sInput As String
sInput = Range("A1").Value
sInput = Application.WorksheetFunction.Trim(Replace(sInput, Chr(10), ""))
Debug.Print sInput
End Sub
Еще один способ избавиться от пробелов
Sub Test2()
Dim x, sOut As String, i As Long
x = Split(Range("A1").Value, Chr(10))
For i = LBound(x) To UBound(x)
sOut = sOut & Application.WorksheetFunction.Trim(x(i))
Next i
Debug.Print sOut
End Sub
Другой подход с использованием Regex
Sub Test_Using_Regex()
Dim sInput As String
sInput = Join(Split(Range("A1").Value, Chr(10)), "")
With CreateObject("VBScript.RegExp")
.Pattern = ">(\s*)<"
If .Test(sInput) Then Debug.Print Replace(Trim(sInput), .Execute(sInput)(0).SubMatches(0), "") '.Replace(sInput, "$1")
End With
End Sub