C:>type en.c

#include <stdio.h>
#include <windows.h>

#define PlainStr "This is a test."

int main(int argc, char * argv[])
{
  BYTE Buff[100];
  FARPROC pEncrypt;
  HINSTANCE hSEMCOMN;
  DWORD dwSize, i;

  hSEMCOMN = LoadLibrary("SEMCOMN.DLL");

  if (hSEMCOMN != NULL)
  {
    pEncrypt = GetProcAddress(hSEMCOMN, "Encrypt");

    if (pEncrypt != NULL)
    {
      dwSize = sizeof(Buff);
      (pEncrypt)(PlainStr, Buff, &dwSize);

      printf("EncStr: ");
      for(i = 0; i < dwSize; i++)
        printf("%c", Buff[i]);
      printf("\n");

      printf("EncStr: ");
      for(i = 0; i < dwSize; i++)
        printf("%x ", Buff[i]);
      printf("\n");
    }
  }

  if (hSEMCOMN)
    FreeLibrary(hSEMCOMN);

  return 0;
}

C:\>type de.c

#include <stdio.h>
#include <windows.h>

#define EncStr1 "\x5b\x06\x86\x01\x26\x7b\xfd\x79\
\x21\x73\xe2\x48\x8f\x79\x8e\xbb\xb4\x2d\xb6\xbb\
\xf2\xe7\x99\x62\xba\x58\x91\xc9\x04\xca\x79\x33"

#define EncStr2 "\x7c\x3b\x57\x65\xee\xe0\x7c\x11\
\x3a\x5a\xe0\x41\xf8\xa3\x21\x16\x63\xb8\xf6\xbe\
\xf7\xd6\xfd\x3f\xb5\x19\x4b\xbe\x6b\xc0\xd9\x53"

int main(int argc, char * argv[])
{

  BYTE Buff1[100], Buff2[100];
  FARPROC pDecrypt;
  HINSTANCE hSEMCOMN;
  DWORD dwSize1, dwSize2, i;

  hSEMCOMN = LoadLibrary("SEMCOMN.DLL");

  if(hSEMCOMN!=NULL)
  {
    pDecrypt = GetProcAddress(hSEMCOMN, "Decrypt");

    if(pDecrypt!=NULL)
    {
      dwSize1 = sizeof(Buff1);
      dwSize2 = sizeof(Buff2);
      (pDecrypt)(EncStr1, sizeof(EncStr1), Buff1, &dwSize1);
      (pDecrypt)(EncStr2, sizeof(EncStr2), Buff2, &dwSize2);

      printf("PlainStr1: ");
      for(i = 0; i < dwSize1; i++)
        printf("%c", Buff1[i]);
      printf("\n");

      printf("PlainStr2: ");
      for(i = 0; i < dwSize2; i++)
        printf("%c", Buff2[i]);
      printf("\n");
    }
  }

  if (hSEMCOMN)
    FreeLibrary(hSEMCOMN);

  return 0;
}