PURPOSE: To constitute a system so that data from a HOST system and data generated by a word processor, etc., can be worked automatically as data processed by an application program by converting attribute information for displaying on a CRT screen, that is, the attribute of display control to a logical delimiter.

CONSTITUTION: The rectangular area 4 of data 2 retrieved from a HOST system, etc., and displayed on a CRT screen 1 is designated, and the data of its area 4 is converted 5 to a form capable of processing by an application program 3 by lumping together the area. That is, at the time of conversion 5, control information (attribute) is deleted, and one byte for showing the end of field data is added as a logical delimiter. Subsequently, to the end of the line, one byte for showing the end of the line is added. Also, to the end of a series of data streams, one byte for showing the end of the data is added. By such a conversion processing, the attribute for displaying on the CRT screen 1 is deleted, and the data stream can be handled in a batch.