how can i substitute this symbol' for = with vba - excel

Question

I'm trying to substitute '. with =
but this code doens't work!
can any one help?
Cells.Replace What:="'.gcmd", Replacement:="=gcmd", LookAt:=xlPart, _
SearchOrder:=xlByRows, MatchCase:=False, SearchFormat:=False, _
ReplaceFormat:=False

Answer 1

If the apostrophe is at the very start of the string, it is a Prefix Character and part of the formatting property of the string, not the value property. It tells excel to treat the value as text.
That being the case, you need to clear the format in addition to replacing the value.
Also note that if you do not have a named formula or range defined on your worksheet, the code will not work returning an application error (unless you define the format as Text).
Code could be something like below:
Option Explicit
Sub due()
Dim R As Range, C As Range
Dim FirstAddress As String
Set R = Range("A1:Z100") 'or whatever
With R
Set C = Cells.Find(What:=".gcmd", Lookat:=xlPart, _
LookIn:=xlFormulas, searchorder:=xlByRows, MatchCase:=False)
If Not C Is Nothing Then
FirstAddress = C.Address
If C.PrefixCharacter = "'" Then
C.ClearFormats
C.NumberFormat = "#" 'omit if `gcmd` is a valid name
End If
C.Value = "=" & Mid(C, 2)
Do
Set C = .FindNext(C)
If C Is Nothing Then Exit Do
If C.Address = FirstAddress Then Exit Do
'Note that you don't really have to test for the apostrophe.
'You could just ClearFormats whether it is present or not.
If C.PrefixCharacter = "'" Then
C.ClearFormats
C.NumberFormat = "#" 'omit if `gcmd` is a valid name
End If
C.Value = "=" & Mid(C, 2)
Loop
End If
End With
End Sub

Answer 2

Or perhaps try this?
(not actually really tested this, just rattled it off as an idea)
Private Sub SOAnswer()
Dim C As Range
Dim Str As String
For Each C In Range("A1: R35") 'Define your range here, or use Sheets(1).UsedRange for all cells on the sheet
If InStr(1, ".gcmd", C.Value) <> 0 Then
Str = C.Value
C.Clear
C.Formula = Replace(Str, ".gcmd", "=gcmd")
End If
Next
End Sub