I have a 3rd party struct that is comprised of the following:

[StructLayout(LayoutKind.Sequential, Size=1)]
public struct BigBlueReasonCodes
{
    public const int ABC_REASONCODE_DESCRIPTION01 = 1000;
    public const int ABC_REASONCODE_DESCRIPTION01 = 1005;
    public const int ABC_REASONCODE_DESCRIPTION01 = 1010;
    public const int DEF_REASONCODE_DESCRIPTION01 = 2001;
    public const int DEF_REASONCODE_DESCRIPTION01 = 2010;
    public const int DEF_REASONCODE_DESCRIPTION01 = 2013;
    public const int GHI_REASONCODE_DESCRIPTION01 = 3050;
    public const int GHI_REASONCODE_DESCRIPTION01 = 3051;
    public const int GHI_REASONCODE_DESCRIPTION01 = 3052;
    public const string JKL_REASONCODE_DESCRIPTION01 = "XYZ;
    public const string GHI_REASONCODE_DESCRIPTION01 = "ST";


  static BigblueReasonCodes();
}

I am trying to look up the reason description(the field name) based on the reason code(the value) so my class can do someting like:

string failureReason = GetReasonDescription(reasoncode);

Somethings of mention are some have int values and some have string values. I am only worried about the ones with int values. I also only want the ones that start with GHI_ if possible but not a big deal.