reverse engineer vba code excel

Question

I am not a VBA programmer. However, I have the 'unpleasant' task of re-implementing someones VBA code in another language. The VBA code consists of 75 modules which use one massive 'calculation sheet' to store all 'global variables'. So instead of using descriptive variable names, it often uses:

= Worksheets("bla").Cells(100, 75).Value

or

Worksheets("bla").Cells(100, 75).Value =

To make things worse, the 'calculation sheet' also contains some formulas.

Are there any (free) tools which allow you to reverse engineer such code (e.g. create Nassi–Shneiderman diagram, flowcharts)? Thanks.

Answer 1

I think @JulianKnight 's suggestion should work Building on this, you could:

1. Copy all the code to a text editor capable of RegEx search/replace (Eg. Notepad++).
2. Then use the RegEx search/Replace with a search query like:
   Worksheets\(\"Bla\"\).Cells\((\d*), (\d*)\).Value

3. And replace with:
   Var_\1_\2

   This will convert all the sheet stored values to variable names with row column indices.
   Example:

   Worksheets("bla").Cells(100, 75).Value    To    Var_100_75
   

4. These variables still need to be initialized.
   This may be done by writing a VBA code which simply reads every (relevant) cell in the "Bla" worksheet and writes it out to a text file as a variable initialization code.
   Example:

   Dim FSO As FileSystemObject 
   Dim FSOFile As TextStream 
   Dim FilePath As String 
   Dim col, row As Integer 
   
   FilePath = "c:\WriteTest.txt" ' create a test.txt file or change this
   
   Set FSO = New FileSystemObject 
    ' opens  file in write mode
   Set FSOFile = FSO.OpenTextFile(FilePath, 2, True) 
    'loop round adding lines
   For col = 1 To Whatever_is_the_column_limit
       For row = 1 To Whatever_is_the_row_limit
        ' Construct the output line
           FSOFile.WriteLine ("Var_" & Str(row) & "_" & Str(col) & _
                          " = " & Str(Worksheets("Bla").Cells(row, col).Value)) 
       Next row
   Next col
   
   FSOFile.Close 
   

Obviously you need to correct the output line syntax and variable name structure for whatever other language you need to use.

P.S. If you are not familiar with RegEx (Regular Expressions), you will find a plethora of articles on the web explaining it.