AutoTools Help w/ appending variable w/ .file extension??

Using a Find My Phone profile I created, using the GetFormattedDate task, I am able to take a picture w/ rear and front cameras while also saving the file using the currentdate/Time Sequence naming series.
So, my file will be something like
%photobombCurrent = year.m.d.hrs.min.001 (not .jpg)
year.m.d.hrs.min.001.jpg
year.m.d.hrs.min.002.jpg

--or at the general time of this post:
2017.12.31.212.49.001.jpg
2017.12.31.212.49.001.jpg

I'm wondering how to utilize the new variable %photobombCurrent and access that in an AutoTools Dialog.
how would I append that .jpg to the end of that variable for AutoTools to associate w/ it?
Additionally, w/ this variable, I'd like to send a join push to the triggered device and so on.