DR-05: Cut Into Previous Recording at Any Point?

[.::Paul::.]

Hello. I'm new to this forum and Tascam gear in general. I've just bought a DR-05 to record samples of ambient sounds in urban settings, and am very impressed by the audio quality and features in this small package. But there is one important feature this recorder seems to lack: the ability to cut into a previous recording at any point, overwrite a portion of that recording with a new one for some time, then resume playback at the cut-out point. What I am describing is exactly the same as (for example) making a recording onto a magnetic cassette tape, playing it back up to a point, stopping playback, cutting-in with a new recording (say a voice note), then resuming playback at that point. This is very common with analogue tapes and one of the greatest in-built features of that medium. Can this be done with the Tascam DR-05 without resorting to external software? I can't imagine why they didn't implement this feature, as that omission would hinder its usefulness as an all-purpose recorder. If this is not possible, is there a portable digital audio recorder that can do what I need, Tascam or no? Thanks.