I hope this will not take too much space...
Ok, if you want to convert txt file to the xls, you have lucky day. Because new Excel format looks like XML, you easily can create code, which makes something like
<?xml version="1.0"?>
<?mso-application progid="Excel.Sheet"?>
<Workbook xmlns="urn:schemas-microsoft-com:office:spreadsheet"
xmlns:o="urn:schemas-microsoft-com:office:office"
xmlns:x="urn:schemas-microsoft-com:office:excel"
xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet"
xmlns:html="
http://www.w3.org/TR/REC-html40">
<DocumentProperties xmlns="urn:schemas-microsoft-com:office:office">
<LastAuthor>basad01</LastAuthor>
<Created>2009-07-16T07:43:44Z</Created>
<Version>11.9999</Version>
</DocumentProperties>
<ExcelWorkbook xmlns="urn:schemas-microsoft-com:office:excel">
<WindowHeight>9090</WindowHeight>
<WindowWidth>13260</WindowWidth>
<WindowTopX>480</WindowTopX>
<WindowTopY>30</WindowTopY>
<ProtectStructure>False</ProtectStructure>
<ProtectWindows>False</ProtectWindows>
</ExcelWorkbook>
<Styles>
<Style ss:ID="Default" ss:Name="Normal">
<Alignment ss:Vertical="Bottom"/>
<Borders/>
<Font/>
<Interior/>
<NumberFormat/>
<Protection/>
</Style>
<Style ss:ID="s21">
<Font x:Family="Swiss" ss:Bold="1"/>
</Style>
</Styles>
<Worksheet ss:Name="blbost">
<Table ss:ExpandedColumnCount="2" ss:ExpandedRowCount="4" x:FullColumns="1"
x:FullRows="1">
<Column ss:AutoFitWidth="0" ss:Width="61.5"/>
<Column ss:AutoFitWidth="0" ss:Width="120.75"/>
<Row>
<Cell ss:StyleID="s21"><Data ss:Type="String">Title 1</Data></Cell>
<Cell ss:StyleID="s21"><Data ss:Type="String">Title2</Data></Cell>
</Row>
<Row>
<Cell><Data ss:Type="String">test1</Data></Cell>
<Cell><Data ss:Type="String">test2</Data></Cell>
</Row>
<Row>
<Cell><Data ss:Type="String">testA</Data></Cell>
<Cell><Data ss:Type="String">testB</Data></Cell>
</Row>
<Row>
<Cell><Data ss:Type="String">testX</Data></Cell>
<Cell><Data ss:Type="String">testY testZ</Data></Cell>
</Row>
</Table>
<WorksheetOptions xmlns="urn:schemas-microsoft-com:office:excel">
<Print>
<ValidPrinterInfo/>
<HorizontalResolution>200</HorizontalResolution>
<VerticalResolution>200</VerticalResolution>
</Print>
<Selected/>
<Panes>
<Pane>
<Number>3</Number>
<RangeSelection>R1C1:R1C2</RangeSelection>
</Pane>
</Panes>
<ProtectObjects>False</ProtectObjects>
<ProtectScenarios>False</ProtectScenarios>
</WorksheetOptions>
</Worksheet>
</Workbook>