Using MATLAB libstruct with DELPHI

I am trying to use a DLL written originally in DELPHI Pascal that has had a C wrapper written to allow MATLAB to use the functions through loadlibrary and calllib. The functions that require integer inputs all work correctly but there is a function that requires the use of a libstruct to pass a string.

The MATLAB prototype file lists the expected input as a 'DelphiShortStringTagPtr' which is a a structure that looks like this:

struct DelphiShortStringTag {
 unsigned char Length;
 char          Data[255];
};
typedef   struct DelphiShortStringTag ShortStringType;

How would I define a libstruct to pass a string into this function call?