Оформил: DeeCo
Автор: http://www.swissdelphicenter.ch

{ 
Question: 

Could anyone point me to any function that can receive 
an HTML style relative path as its input and return a full path as its 
output based on the exe's current location, e.g 

Input: '..\..\test2.dat' 
Output: C:\folder1\test2.dat 

(assuming that the executable is running from 
 C:\folder1\folder2\folder3\Project1.exe) 

}

 { 

Answer: 

PathCombine() Concatenates two strings that represent properly 
formed paths into one path, as well as any relative path pieces. 
}

 function PathCombine(lpszDest: PChar; const lpszDir, lpszFile: PChar):
 PChar; stdcall; external 'shlwapi.dll' name 'PathCombineA';
 function PathCombineA(lpszDest: PAnsiChar; const lpszDir, lpszFile:
 PAnsiChar): PAnsiChar; stdcall; external 'shlwapi.dll';
 function PathCombineW(lpszDest: PWideChar; const lpszDir, lpszFile:
 PWideChar): PWideChar; stdcall; external 'shlwapi.dll';

 { 
 Requires Windows 2000 (or Windows NT 4.0 with Internet Explorer 4.0 or later); 
 Requires Windows 98 (or Windows 95 with Internet Explorer 4.0 or later) 
}

 procedure TForm1.FormCreate(Sender: TObject);
 var
   dest: string;
   BaseFile, RelativePath: String;
 begin
   BaseFile := 'C:\folder1\folder2\folder3\';
   RelativePath := '..\..\test2.dat';
   SetLength(dest, MAX_PATH);
   PathCombine(@dest[1], PChar(ExtractFilePath(BaseFile)), PChar(RelativePath));
   SetLength(dest, StrLen(@Dest[1]));
   ShowMessage(dest);
 end;

 { 
  The ExtractRelativePath function takes a base directory but the 
  ExpandFilename function does the expansion based on the current 
  directory not a given base path. 
}

 RelativePath := ExtractRelativePath(ExtractFilePath(BaseFile), TargetFile);