It is a fact of life that the macro recorder will not record all commands, and it doesn't often use the most efficient code. If you want to insert a check box using VBA you will have to do it manually. You didn't say what kind of check box, but assuming that you want to insert a legacy form field check box at the cursor position the code would be
Dim oFld As FormField
Set oFld = ActiveDocument.FormFields.Add(Selection.Range, wdFieldFormCheckBox)
oFld.CheckBox.Value = True 'or False
I don't know which Legacy toolkit you are referring to, but it may be Greg Maxey's useful ribbon addition http://gregmaxey.mvps.org/word_tip_p..._controls.html. However this will not affect the issue regarding the macro recorder.