Specific dice rolls with variable to store

[Ferns]

Greetings, I am trying to create a !roll command in which players may roll dice with variables, for example 3d-2 and store that variable for later use.
I can't find a way to have that done tho, any ideas?

[Ferns]

Ok, I got this kinda done by getting a parameter as number of dice, than running a custom script multiplying the parameter by 6. Used the number of dice as minimum and the custom script result as maximum for a random number generation.
At first it seems to be working fine, tho it tends to repeat a lot the same numbers and just going to some other numbers a few times, either the random number generator is not workin properly or I screwed something up.
Now I can't get to run another script to do the maths with the second parameter, it just says it in the message, like 4-2 or 4+1.