Variable code in advanced editor

I'm wondering if I can replace a piece of code in the advanced editor with a parameter (or something else) that contents the same piece of code. For example, if I want to change the type of each column:

1) This is the line recorded by Power Query Editor, and I want to replace the bolded code with a parameter (because the numbers of columns can change in this query, and also the columns name can change):

#"Changed Type" = Table.TransformColumnTypes(#"Promoted Headers", {{""Etap"", Int64.Type}, {""Ser."", Int64.Type}, {""Bloq"", Int64.Type}}),

2) Then I create a text parameter, named Parameter1, with the following value:

 {{""Etap"", Int64.Type}, {""Ser."", Int64.Type}, {""Bloq"", Int64.Type}}

3) And try to replace the parameter in the advanced editor line (I'm not sure of the syntax):

#"Changed Type" = Table.TransformColumnTypes(#"Promoted Headers", Parameter1),

4) But this error message is displayed:

Let me know if there is any other way to replace a piece of code with something else instead of a parameter. Mainly because I have a variable number of columns in a query.

Thank you in advance for your help.