The numbers tell the computer what characters to take from the string. Each number refers to the characters place in the scentence, for example:
1 2 3 4 5
H E L L O
H is number 1, so if I wanted to set my variable to whatever value the player entered in the place where H is, I would use Substring, 1, 1. This means it just takes the first character in the string. When the two numbers are different, this means it's taking a range of characters, and the two numbers give the start and end points. So using the word hello again Substring, 1, 4 would take every letter between and including those at positions 1 and 4, so you would end up with the word HELL.
So basically, in that trigger I gave you, the first bit, Substring, 12, 12 is taking the 12th character in the entered chat string. I use 12 because that is the postion in the scentence that the player number is going to be located:
1. -
2. i
3. n
4. c
5. o
6. m
7. e
8. s
9. e
10. t
11.
12. 1
13.
14. 1
15. 0
16. 0
17. 0
Then I used Substring 14, 17 to find the range of characters in the positions that the income amount should've been entered into.
I hope that makes sense
And I'm glad I could help you sort your problem!