+$!
+$! If specified, replace final ".P7]" with part of P4.
+$!
+$! This allows a system-specific subdirectory name on a
+$! dependency file to be replaced with an MMS macro, for
+$! example, ".ALPHA]" with ".$(DEST)]".
+$!
+$ if (dest .nes. "")
+$ then
+$ dest_dot_loc = f$locate( dest, back)
+$ if (dest_dot_loc .lt. f$length( back))
+$ then
+$ back = f$extract( 0, dest_dot_loc, back)+ -
+ f$extract( 1, 1000, prefix)+ -
+ f$extract( (dest_dot_loc+ f$length( dest)), 1000, back)
+$ endif
+$ endif
+$!
+$! Replace null subdirectory with "000000".
+$!
+$ if (f$length( back) .gt. 0)
+$ then
+$ mid = p6
+$ else
+$ mid = "000000]"
+$ endif
+$!
+$ line = front+ mid+ back