.NET 2.0 does have odbc.
To get the worksheets using odbc, I guess you can use the GetOleDbSchema() to get the schema and go through each row using the "TABLE_NAME" column to get the worksheet name.
Dim theDataTable as new DataTable()
theDataTable = objConn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, nothing);
for each currentRow as DataRow in theDataTable
does this help