data c1c2;
infile 'F:\gmotion1\muw0830309292322.txt';
input w muw dmuw;
w3=w**3;
w2=w**2;
;
proc nlin;
parms a1=0 a2=0 a3=0 a4=0 b1=0 b2=0 b3=0 b4=0;
model dmuw=(a1+a2*w+a3*w2+a4*w3)*muw+b1+b2*w+b3*w2+b4*w3;
output out=c;
FILENAME B DDE 'excel|[F:\Book1.xls]sheet1!r1c1:r1c8' notab;
data _null_;
file B;
t='09'x;
put c;
run
;
运行后显示：

NOTE: Variable c is uninitialized.
ERROR: Physical file does not exist, excel|[F:\Book1.xls]sheet1!r1c1:r1c8.
NOTE: The SAS System stopped processing this step because of errors.
NOTE: DATA statement used:
      real time           0.00 seconds
      cpu time            0.00 seconds

但这个文件我已建好并打开了，为什么会说不存在呢？

盼高手解答！