Replace cell content in Excel with array content - excel

Question

I have an Excel worksheet which includes a text column which stores both text and numbers. I am trying to extract serial numbers, which are 13 digits long, and replace the column content with these serial numbers. I was able to extract the serial numbers but I am stalling on how to replace the cell.value with the serial numbers. Below is my initial approach:
Sub extract_digits()
Dim cell As Range
Dim arr As Variant, arrElem As Variant
Dim final_arr As Variant
With Worksheets("Test_1")
For Each cell In .Range("H5", .Cells(.Rows.Count, "H").End(xlUp))
arr = Split(Replace(cell.Value, " ", " "), " ")
For Each arrElem In arr
If Len(arrElem) = 13 Then MsgBox arrElem
Next arrElem
Next cell
End With
End Sub

Answer 1

The second option (Remove Letters From Strings/Numbers/Cells With User Defined Function) from this site should do the trick:
https://www.extendoffice.com/documents/excel/3244-excel-remove-letters-from-strings-cells-numbers.html
Function below is from above website, it's not mine
Function StripChar(Txt As String) As String
With CreateObject("VBScript.RegExp")
.Global = True
.Pattern = "\D"
StripChar = .Replace(Txt, "")
End With
End Function
How is this working
Is using Regular Expressions (RegEx). The .Pattern means it's looking for any non numeric (ie 0 to 9), it's then using the .Replace function to replace any non numeric with nothing.
How do you use this
Option 1 You can either use it directly in a column next to your column, eg =StripChar(H5) and then just copy that formula down.
Option 2 Alternatively using your code
Sub extract_digits()
Dim cell As Range
Dim arr As Variant, arrElem As Variant
Dim final_arr As Variant
With Worksheets("Test_1")
For Each cell In .Range("H5", .Cells(.Rows.Count, "H").End(xlUp))
cell = StripChar(cell.Value)
Next cell
End With
End Sub