You gave your own examples, but you ignored mine, so I still don't know whether my examples reveal any special needs. Let me ask again, but more wordily:

a) You say in the case of 'N' you "don't want to have anything". But (to be ridiculously technical about it) there's no such thing as not having anything; your program can take a number of different actions. It can skip that line and not react to it (which I guess can be thought of as not having anything, after all). Some people think of the space character as "not anything"—not most people, but it does happen. The most obvious candidate for "not anything" is the null string, ""; but more knowledgeable programmers would insist that the correct value is Null, which is something different. In Excel I think the Empty value is another one again. So my first question is this: When there's an 'N' in the second position (ie between the first and second slash), do you want your program to come up with "", or what?

b) I didn't ask this before, but what about 'n' (lower case); should it be treated as data, or the same as 'N'?

c) I assume that there's no situation in which you want 'N' to be the data itself?

d) Is there ever a case where the string is "-DR//FRU/2574/C.Q6"? Because if there is, I sort of assume your logic should treat it identically to "-DR/N/FRU/2574/C.Q6".

e) What about when the string is "-DR/"? Again, should it be treated the same as "-DR/N"?

If your answer is the same in all cases, then I think the Split function (as I described in my last entry) should work for you.