Find cell with text, offset to the left one cell and write code

Something like this maybe

Sub timas()
Dim i As Long
For i = Range("B" & Rows.Count).End(3).Row To 2 Step -1
    If InStr(1, Cells(i, "B").Value, "Rail bracket", vbTextCompare) > 0 Then
        Select Case ExtractNumber(Cells(i, "B"))
            Case Is = "63"
                Cells(i, "A") = 227372063
            Case Is = "75"
                Cells(i, "A") = 227372075
            Case Is = "90"
                Cells(i, "A") = 227372090
        End Select
    End If
Next i
'40 - 227372040
'50 - 227372050
'56 - 227372056
'63 - 227372063
'75 - 227372075
'90 - 227372090
'110 - 227372110
'125 - 227372125
'160 - 227372160
'200 - 227372200
'250 - 227372250
End Sub

Function ExtractNumber(rC As Range) As String
    With CreateObject("VBSCRIPT.REGEXP")
        .Pattern = "[^0-9]"
        .Global = True
        .IgnoreCase = True
        ExtractNumber = .Replace(rC.Value, "")
    End With
End Function