Excel VBA - Replacing Value

Question

I want to replace the numbers 91, 92, 93, 94, 99 with 91H, 92H, 93H, 94H, 99H. But every time I run the macro a second time, the macro adds another H to the number and it looks like 91H H for example. I can't find a solution for this. I don't want that the macro adds another H to the number. I want that the macro only adds a H to the new values, not to the ones that have already been changed.

Columns("D").Replace What:="92", _
                        Replacement:="92H", _
                        LookAt:=xlPart, _
                        SearchOrder:=xlByRows, _
                        MatchCase:=False, _
                        SearchFormat:=False, _
                        ReplaceFormat:=False
Columns("D").Replace What:="93", _
                        Replacement:="93H", _
                        LookAt:=xlPart, _
                        SearchOrder:=xlByRows, _
                        MatchCase:=False, _
                        SearchFormat:=False, _
                        ReplaceFormat:=False

Columns("D").Replace What:="91", _
                        Replacement:="91H", _
                        LookAt:=xlPart, _
                        SearchOrder:=xlByRows, _
                        MatchCase:=False, _
                        SearchFormat:=False, _
                        ReplaceFormat:=False

Columns("D").Replace What:="94", _
                        Replacement:="94H", _
                        LookAt:=xlPart, _
                        SearchOrder:=xlByRows, _
                        MatchCase:=False, _
                        SearchFormat:=False, _
                        ReplaceFormat:=False

Columns("D").Replace What:="99", _
                        Replacement:="99H", _
                        LookAt:=xlPart, _
                        SearchOrder:=xlByRows, _
                        MatchCase:=False, _
                        SearchFormat:=False, _
                        ReplaceFormat:=False

I didn't post the whole VBA code because it's a little bit long.

Answer 1

I think of a workaround. Add codes before the macro to replace 91H, 92H, 93H, 94H, 99H with 91, 92, 93, 94, 99. What the new macro would do is:
A. "91H": remove "H" and add "H", ie do nothing
B. "91": dont fit into first part, "H" will be added in 2nd part

This should work for any text seen.

Answer 2

In general, you are repeating lots of code. This should be avoided. A way to do it is like this:

Option Explicit

Sub ReplaceSomething(columnName As String, lookFor As String, replaceWith As String)

    Dim rngCol      As Range
    Dim rngCells    As Range

    If WorksheetFunction.CountA(Columns(columnName)) = 0 Then Exit Sub
    Set rngCol = Columns(columnName).SpecialCells(2)
    If rngCol Is Nothing Then Exit Sub

    For Each rngCells In rngCol
        If rngCells = lookFor Then
            rngCells = replaceWith
        End If
    Next rngCells

End Sub

Sub TestMe()

    ReplaceSomething "A", "H", "H1"
    ReplaceSomething "B", "H", "H1"
    ReplaceSomething "D", "H", "H1"

End Sub

Thus you would be giving the Column Name as an argument of the function ReplaceSomething and it will run for columns A, B and C.