You can use your file to define your variables by get line
by line and set accord to the item/var_name in loop by...
For Bat/Cmd file:
(for %%i in (%_var%)do set/p %%~i=)<.\file.txt
For one line:
@(for %%i in (ABC,PQR,XYZ)do @set /p %%~i=)<.\file.txt
Obs.: Note two things, one that my poor / weak English, the second is that the first 3 lines cannot be blank