Help on IF function to calculate rent increase

Hi Guys,

Could someone please help me out.

On the attached spreadsheet I am trying to show a property which has an original lease running until 2030 that increases by inflation each year. So far so good, row 86, 87 and 88 has got it going fine I think.

What I want to do now is show that after this ends, a new extended lease starts after period 45 (row 51), commencing with the Extended rent figure in C42. Again this is working in row 68, however now I have lost my inflation increase, I am just getting the rent split into four repeatedly.

Could someone please tell me how I combine my successful rent calculation from the current cash flow with the successful lease extension calculation from 68,69,70. Ie what is the IF function that says if E41 is greater than E51 then E68 equals C40/4, however if that is successful then subsequently the rent increases each year by the extended inflation.

thank you in advance