I need to turn my Mathematica output (in string form) to a form that I then need to feed to Maple, and specifically I'd need all multiplications to be marked by * (as opposed to x or, as it happens now, an empty space). How do I get the program to do that?

eg. 2 nu2 b -> 2*nu2*b

(on the other hand, not all spaces correspond to multiplication signs so I can't just replace those..) Thanks in advance, cheers! S