I need to generate doc (real doc, not docx) files, the "best" way i have found is to use word automation (Word 2010). I have files that I open, and then replace values inside before saving it on a new name. (Ex : I replace "" with "155023"). To do this, I use the Application.Selection.Find. I just had a problem when the new value had more than 255 characters (Thanks Microsofts limitations ...). To avoid this problem, i use TypeText in this case. My problem now is once I use TypeText, the Replace do not work anymore .. And I can't find why. Any idea will be greatly appreciated. My code is in a function, called in a foreach with each values to replace : private void Replace(Application app, string name, string newValue) { Selection selection = app.Selection; Find find = selection.Find; Replacement replacement = find.Replacement; find.ClearFormatting(); find.Text = "<" + name + ">"; // Word limitation : can't replace with more than 255 characters, // use another way to do it if that's the case if (tempNewValue.Length < 255) { replacement.ClearFormatting(); replacement.Text = tempNewValue; find.Execute(Replace: replaceAll); } else { while (find.Execute()) { selection.TypeText(tempNewValue); } } Marshal.ReleaseComObject(replacement); Marshal.ReleaseComObject(find); Marshal.ReleaseComObject(selection); }