Have a look here:
How to: Get Data from Multiple Workbooks using One OleDbConnection?[
^]. It might help you.
If you want to select only part of 'table', you need to use:
SELECT <ColName1>, <ColName2>, <ColNameN>
FROM [WorksheetName$A1:G500]
If you have named ranges,
SELECT <ColName1>, <ColName2>, <ColNameN>
FROM [NamedRange]
To be able to join data from another sheet, use:
SELECT t1.<ColName1>, t1.<ColName2>, t2.<ColName1>, t2.<ColName2>
FROM [Worksheet1$A1:G500] AS t1 INNER JOIN [Worksheet2$A1:G500] AS t2 ON t1.ColName1 = t2.ColName3
If the data type for each column in Sheet1 corresponds to data type for each column in Sheet2, use:
SELECT <ColName1>, <ColName2>, <ColNameN>
FROM [Worksheet1$A1:G500]
UNION ALL
SELECT <ColName1>, <ColName2>, <ColNameN>
FROM [Worksheet2$A1:G500]
If you want to recognize the source of data, here is simple trick:
SELECT 'Sheet1' AS SheetName, <ColName1>, <ColName2>, <ColNameN>
FROM [Worksheet1$A1:G500]
UNION ALL
SELECT 'Sheet2' AS SheetName, <ColName1>, <ColName2>, <ColNameN>
FROM [Worksheet2$A1:G500]
Good luck!