Check this good FAQ on this topic

http://www.levelextreme.com/ViewPageNewFAQ.aspx?ID=7841


>I am using the following code and it works fine
>
>

>SELECT New_Bills
>SCAN  && Scans for New_bills up to EOF()
>*Define Variables
>	cPsfilepath=ALLTRIM(Myfilepath)
>	CREATE CURSOR Billcompress (POS C(254)) && Create Temporary Cursor
>	SELECT Billcompress
>	APPEND FROM '&cPsFilepath' SDF
>

>
>However when I use APPEND FROM cPsFilepath SDF, it generates error as file not found.
>
>My Questions.
>(1) IS it necessary to have Macro substitue. ?
>(2) Where and Why Macro Substutes are used ?
>(3) Does use of Macro substitue decreese the processing speed ?
>
>Kinldy Guide