就是在filename temp DDE 'EXCEL|sheet1!r2c1:r200c4'这样的DDE命令中单引号引用的部分
用|和!相隔的三个部分，称为DDE triplet

直白点说就是：应用程序的名字|文件的路径！范围
The triplet takes the following form:


'application-name|topic!item'  


where:

application-name
is the executable filename of the server application. For example, the application-name for Microsoft Word is winword , and for Microsoft Excel it is excel .

topic
is the topic of conversation (between SAS and the DDE server application). This is typically the full path filename of the document or spreadsheet with which you want to share data.

item
is the range of conversation specified between the client and server applications. In spreadsheet applications, this is usually a range of cells. For document-based applications (for example, Microsoft Word), the item is something that defines a location in the document, such as a bookmark.