I just want to ask in the first place if such thing is possible...
Are you asking whether delays are possible? Olipcs already told you that they are. But in both your examples (frostbolt and formations) delays are against the rules.

Or are you asking whether you can do formations without breaking the rules? Yes. Here's one way to do it. Make two hotkeys. One moves the main. The other moves the slaves. Choose trigger keys (the keys you press with your fingers) that are side-by-side on the keyboard. The way you use them is, press them simultaneously but release the main key a little bit before the other key. It's a very easy physical gesture.