my problem is the following.

Since I have a numerical integration method implemted in my excel
sheet I have a huge amount of rows containing data which I can find
the value I need with vertical lookup. However, I would like to give
it a go with VBA.

I want to work with little steps, which keeps on adding up "tt" till
the desired value.

tt = Range("A35")
dt = Range("B38")
xt = Range("35B")

If xt = xt Then tt = tt + dt

I tried the above. but he only does it once, and i want it to keep on
going. I´ve searched the web and hit help function. I guess I have to
use the Do..Loop function. Anyone who knows how to fix this.

It is cell A35 which have to ascent.