Bot Command with Dice: "!100d100"

'''

I want to do this: When I write !10d6, 10 dices of 6  "bases" are thrown.
I will return the sum of their indexes.

'''

import random

# AUXILIARY FUNCTION
def throwDice(command):

    if command[0] != "!":
        print("Command must begin with '!'.")
    else:
        # I will try to find the 'd' character
        didIfindTheDCharacter = False
        indexOfDCharacter = -1000
        for i in range(0, len(command)):
            if command[i] == 'd':
                didIfindTheDCharacter = True
                indexOfDCharacter = i
                break

        # Check if I have found the 'd' character
        if didIfindTheDCharacter == False:
            print("The command begins with the appropriate prefix = '!', but misses the 'd' character.")
        else:
            # The command contains '!' and 'd'
            firstNumberAsString = command[1:indexOfDCharacter]
            secondNumberAsString = command[indexOfDCharacter+1:len(command)]
            firstNumber = int(firstNumberAsString)
            secondNumber = int(secondNumberAsString)

            # Now, I will start the process for producing what I want
            sumOfDiceIndications = 0
            for i in range (0, firstNumber):
                sumOfDiceIndications += random.randint(0, secondNumber)

            return sumOfDiceIndications

# MAIN FUNCTION
while 0 == 0:
    command = input("Write command: ")
    print(throwDice(command))
    print()