(weird, the system just deleted PART of my post!)

If your data is not consistent, it's either going to have to be cleaned up so that it is or you're going to have to live with problems.  Data being different lengths is not always a problem as long as the left-aligned significant parts are consistent.

Assuming the data element's definition is something like this: "Element starts with a D, contains one or more zeroes, contains a single numeric digit, followed by one letter" then it can be cleaned up through string manipulation possibly with pattern matching.

But not knowing what rules build that value, it's hard to offer a good solution.