Like to find an answer too a long calculation in one cell, but the formule
become to long just before I'm finish.
A loop would have done it but I have no skills for to make it. what can I do
to get around it? have tryied in many ways but excel do not let me get an
answer to this.

What can I do?

Formula goes like this:

=MMULT(MINVERSE(MMULT(TRANSPOSE(
OFFSET($L$80;DAG;0;Nobs;aksjer):OFFSET($L$80;DAG;0 ;Nobs;aksjer)-TRANSPOSE(MMULT(TRANSPOSE(
OFFSET($L$80;DAG;K$78;Nobs;aksjer):OFFSET($L$80;DA G;K$78;Nobs;aksjer));R80:R109)/Nobs));
OFFSET($L$80;DAG;0;Nobs;aksjer):OFFSET($L$80;DAG;0 ;Nobs;aksjer)-TRANSPOSE(MMULT(TRANSPOSE(
OFFSET($L$80;DAG;K$78;Nobs;aksjer):OFFSET($L$80;DA G;K$78;Nobs;aksjer));R80:R109)/Nobs))/(Nobs-1));
MMULT(TRANSPOSE(
OFFSET($L$80;DAG;K$78;Nobs;aksjer):OFFSET($L$80;DA G;K$78;Nobs;aksjer));R80:R109)/Nobs-U101)/

SUM(MMULT(MINVERSE(MMULT(TRANSPOSE(
OFFSET($L$80;DAG;0;Nobs;aksjer):OFFSET($L$80;DAG;0 ;Nobs;aksjer)-TRANSPOSE(MMULT(TRANSPOSE(
OFFSET($L$80;DAG;K$78;Nobs;aksjer):OFFSET($L$80;DA G;K$78;Nobs;aksjer));R80:R109)/Nobs));
OFFSET($L$80;DAG;0;Nobs;aksjer):OFFSET($L$80;DAG;0 ;Nobs;aksjer)-TRANSPOSE(MMULT(TRANSPOSE(
OFFSET($L$80;DAG;K$78;Nobs;aksjer):OFFSET($L$80;DA G;K$78;Nobs;aksjer));R80:R109)/Nobs))/(Nobs-1));
MMULT(TRANSPOSE(
OFFSET($L$80;DAG;K$78;Nobs;aksjer):OFFSET($L$80;DA G;K$78;Nobs;aksjer));R80:R109)/Nobs-U101))