create a row number based upon return of a function

how do I reference a row number based upon some value of a function?

My data is in Column B. But the actual row number depend on some other condition.

ideally, I want something like this in my formula

=T("the actual value is "&sheet1.B(rowNumber(output of function)))

if the output of a fuction is “23”, then, essentially I will see

=T("the actual value is "&sheet1.B23)

With INDIRECT() you can get it. Also it can be done with INDEX() and OFFSET().

edited 20190403

With INDIRECT you need to compose text of the address:
T("the actual value is "&INDIRECT("sheet1.B"&(rowNumber(2+3)))

with INDEX() the position on the range
T("the actual value is "&INDEX(sheet1.B1:B500;rowNumber(2+3)))

with OFFSET() is a displacement from the beginning of the range
T("the actual value is "&OFFSET(sheet1.B1;rowNumber(2+3)))

much appreciate your answer. I actually was aware of three functions. except that I am having problem understand how to use them.

if you happened to have example on how to use it, please spoon feed me.

using my example, how to use indrect() / index() / offset(), assuming “output of my fuction” is simply “2+3”?

=T("the actual value is "&sheet1.B(rowNumber(2+3)))