ADO.NET Connection Strings

ODBC Driver for Excel

strConnection = _T("Driver={Microsoft Excel Driver (*.xls)};DriverId=790;" bq=C:\\DatabasePath\\DBSpreadSheet.xls;
DefaultDir=c:\\databasepath;");

ODBC Driver for Text
strConnection = _T("Driver={Microsoft Text Driver (*.txt; *.csv)};" "Dbq=C:\\DatabasePath\\;Extensions=asc,csv,tab,txt;");

Refer Connectionstrings