The settings change depending on the database or server. To find the current settings, you can display the TStringList returned from GetAliasParams in a TMemo, then you can modify the alias by replacing specific indexed strings within the TStringList.

void __fastcall TForm ::Button Click(TObject *Sender)
{
   TSTringList MyList;
   MyList = new TStringList();
   Session ->GetAliasParams('DBDEMOS', MyList);
   Session ->Memo ->Lines->Assign(MyList);
   Session ->MyList->Strings[0] = "PATH=d:\\borland\\BCB\\Demos\\Data';
   Session ->ModifyAlias('DBDEMOS', MyList);
   delete MyList;	
}