Internal and external mic. use?

Hi all (first ever post here!) I've just received some AMs from LabMaker and aim to add on the 3.5mm jack socket so I can use electret condenser mics. in addition to the existing internal one (in the hope of more placement flexibility and having the ability to test the mic. too). According to the note on here around adding the jack it states that inserting a mic. into the jack will change the mic. default to the new external one over the internal one. However, is there possibly a way to choose which mic. is used during a recording period? I'm wondering if I can adopt a 'day and night' type recording pattern where during the day the external mic. is in use at 48000 but at night the AM switches to record much higher ultrasonic frequencies via its' internal mic. in order to capture bats (and possibly any other ultrasonic calls from other taxa i.e. small mammals or orthoptera). Could a config file be generated for this or is it more of a 'hardware' incompatibility issue? Thanks.