Today you see that more and more laptops do not make a separate mic/in and headphone/out 3.5mm jacks, instead making use of a single 3.5mm jack that supports both mic/in and headphone/out.
Because of this reason, it is not possible to use a normal cable to make use of our LTC Timecode options.
If you do wan't to make use of LTC time code capabilities, with a single mic/headphone port, all you would need to do is make use of a simple splitter as shown below.
This will separate the mic/in and headphone/out so you can directly connect to the mic/in.