Change table source from Salesforce to excel

Hello,

I have a query which source is linked to a salesforce report (I don't have the credentials), and I would like to change its source to a local excel file on my local drive. However, when I try to change the source, the pop-up that I get only show the options to change the salesforce source, but I cannot choose a local excel file.

What I did is to change directly the code in the Advanced Editor. The initial code I have was:

     Initial code:

       Let

          Source = Salesforce.Reports(),
          #"00O1o000004gOEjEAM" = Source{[Name="00O1o000004gOEjEAM"]}[Data],
          #"Expanded CV (converted)" = Table.ExpandRecordColumn(#"00O1o000004gOEjEAM", "CV (converted)", {"amount",                       "currency"}, {"CV (converted).amount", "CV (converted).currency"}),
          #"Expanded Weighted CV (converted)" = Table.ExpandRecordColumn(#"Expanded CV (converted)", "Weighted CV                            (converted)", {"amount", "currency"}, {"Weighted CV (converted).amount", "Weighted CV (converted).currency"}),
          #"Added Date.StartOfMonth" = Table.AddColumn(#"Expanded Weighted CV (converted)", "Date.StartOfMonth", each                     Date.StartOfMonth([Contract Sign Date])),

New code I wrote:

       let
          Origen = Excel.Workbook(File.Contents("C:\Users\PowerBIfiles\Book_v.0.3.xlsx"), null, true),
          report1540539768565_Sheet = Origen{[Item="report1540539768565",Kind="Sheet"]}[Data],
          #"Encabezados promovidos" = Table.PromoteHeaders(report1540539768565_Sheet, [PromoteAllScalars=true]),
          #"Expanded CV (converted)" = Table.ExpandRecordColumn(#"Encabezados promovidos", "CV (converted)", {"amount",                     "currency"}, {"CV (converted).amount", "CV (converted).currency"}),
          #"Expanded Weighted CV (converted)" = Table.ExpandRecordColumn(#"Expanded CV (converted)", "Weighted CV                               (converted)", {"amount", "currency"}, {"Weighted CV (converted).amount", "Weighted CV (converted).currency"}),
           #"Added Date.StartOfMonth" = Table.AddColumn(#"Expanded Weighted CV (converted)", "Date.StartOfMonth", each                     Date.StartOfMonth([Contract Sign Date])),

It worked to change the source to my excel file, because I can see the table in PBI as it is on excel. However, there is an error in the #"Expanded CV (converted)" and #"Expanded Weighted CV (converted)" steps. 

This is the table on the #"Encabezados promovidos" step:

And this is the table in the #"Expanded CV (converted)" step:

This is the step applied:

Does anyone know what might be the problem? 

Thank you very much for your help.

Ignacio