The example below shows how to apply a format to multiple variables when writing a fixed format raw data file. You need parentheses around x2-x3 and f1. to tell SAS that these should be grouped together. Without the parentheses (and try it for yourself!), the f1. format only applies to x3.
data temp0; input x1-x3; cards; 1 2 3 4 5 6 7 8 9 ; run; data _NULL_ ; file "rawdata.txt"; set temp0; put x1 F4. (x2-x3) (F1.); run;
and the result, in "rawdata.txt" is
123 456 789