Urgent Requirement: Extract key from txt file using batch command and assign to variable

The key will look like this D2GJ5928-F29G-4P19-8290-222FD9F08925. It will always be 32 digits and seperated by - and same number of digits as example before and after - but it can be either starting with number or alphabet. It has to run as a single batch command and assign it to a variable