For MS-DOS, the mode command is probably the best you'll find. You can use mode con:lines=50 for example to change from 25 lines to 50 lines on-screen.
MS-DOS itself operates in text mode, so the actual screen resolution itself is largely measured in characters like this.
Mind you, I recall, ages ago, on my 386 that my Trident Video Card's drivers included a utility that could crank up the number of lines up to 100 and somehow had MS-DOS itself working through a graphics mode, but I don't know the details of that.
For Windows you could use a utility like multires. Or write your own program to call from the batch file which changes the resolution.
