power query how to extract data from text file - powerquery

Question

I have a text file - in fact a report - that has several pages, each page having a header and a footer. The header has a string that indicates the topic covered in the body of the page. I would like to extract the body of the pages that relate to a specific topic. Headers and Footers have the same number of lines, and body has the same structure as shown in an example at the bottom of the note. How to extract the information about claims type BBB only ?
The number of rows to skip at the top of the report is unknown, as well as the number of rows to drop at the bottom of the report. Could somebody point me in the right direction ? Thank you.
Page 1
Claims type: AAA
Claim # Amount $
11111 10
11112 20
.....
End of Page 1
Page 2
Claims type : AAA
...etc.
End of Page 2
Page 3
Claims type : BBB
Claim # Amount $
21111 100
21112 200
.....
End of Page 3
Page 4
Claims type : CCC

Answer 1

You Can do it with UI only:
let
Source= Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
AddCustom = Table.AddColumn(Source, "Custom", each if Text.Start([Column1],6)="Claims" then Text.End([Column1],3) else if Text.Start([Column1],6)="End of" then "Trash" else null),
ReplErrs = Table.ReplaceErrorValues(AddCustom, {{"Custom", null}}),
FillDown = Table.FillDown(ReplErrs,{"Custom"}),
FilterBBB = Table.SelectRows(FillDown, each ([Custom] = "BBB")),
Rem1st = Table.Skip(FilterBBB,1),
Promoted = Table.PromoteHeaders(Rem1st)
in
Promoted

Answer 2

I don't think there's a way to do this purely through the UI. You'll want to use the Table.PositionOf and List.PositionOf methods.
Here is what I have:
let
Source = Table // however you get the table
#"Position of Claims" = Table.PositionOf(Source, [Column1 = "Claims type : BBB", Column2 = null]),
// Remove entries above the table belonging to Claims type BBB.
#"Remove Top Rows" = Table.Skip(Source, #"Position of Claims" + 2),
// Check which column has the "End of Page" tag
#"Added Custom" = Table.AddColumn(#"Remove Top Rows", "Custom", each if [Column1] is text and Text.StartsWith([Column1], "End of Page") then 1 else 0),
#"Position of End of Page" = List.PositionOf(#"Added Custom"[Custom], 1),
// Remove rows that don't belong to this page's table
#"Remove Bottom Rows" = Table.FirstN(#"Added Custom", #"Position of End of Page"),
// Remove the column that told us which row had End of Page on it
#"Removed Columns" = Table.RemoveColumns(#"Remove Bottom Rows",{"Custom"})
in
#"Removed Columns"`