var
  tmpPart: String;
Begin
(*
BBL folder1
ABB folder2
BYR folder4
BYP folder5
DAT folder6
*)
  psExitCode:= 1;
  psVSA := '';
  // ... add your code here
  tmpPart := copy(psFileName, 1, 3);
  If SameText('BBL', tmpPart) then
    psVSA := 'folder1';
  If SameText('ABB', tmpPart) then
    psVSA := 'folder2';
  If SameText('BYR', tmpPart) then
    psVSA := 'folder4';
  If SameText('BYP', tmpPart) then
    psVSA := 'folder5';
  If SameText('DAT', tmpPart) then
    psVSA := 'folder6';   
End.