Forums Scripts & Popups Getting topic and saving it to %var

I'm working on a script that would change a specified channel's topic every 0:00am so that the topic first looks like this (for example): "TTG:91 other text" and after the idea is to replace the TTG:91 with TTG:90 next day and TTG:89 the following day.

I think it's easier to deal with the topic in multiple parts, so that one %var contains the number that will be reduced by 1 every 0:00 and the other topic would be saved in it's own %var.