Dynamic conditional formatting

Hi, I've been looking around a lot already and tried a few things, but I think I need some help with the following.

I have two tabs. On the first tab, I have a table(1) that is growing per use case in width. On the second tab, calculations are made in table(2), always based on the last 30 columns of table(1), making sure only the last 30 columns of table(1) are considered. Now my goal is that, based on the 30 columns in table(2), only the last 30 columns of table(1) have conditional formatting.

My first idea was to put a row above table(1), with that via some counting always places hard references into the last 30 columns, such as 'Sheet2!A1:Z30', and use INDIRECT in the formula for conditional formatting. But this didn't work. Hoping I can find some other ideas here! Thanks for thinking with me