Average first n non-zero results in a row

[gooniegirl180]

I have a row of dates from row C5:U5.
In column A are a list of products: column B contains a "Switch", Column C contains an average, and column W may or may not contain start date.

If the switch for a product is AVG, I want the result in column X to be the figure in column C. Easy.
If the switch for a product is FOR, I want the result in column X to be the average of the first 8 non-zero columns. Doable.
If the switch for a product is PRE, I want the result in column X to be the average of the first 8 non-zero columns from (and including) the start date onwards. If there are less than 8 non-zeros, such as in example G below, I want the average of the number of non-zero values. There may be any number of zero values from the start date before the values kick in, but I still want the average of the first 8 values.

Any help would be gratefully received! Thanks!

 

[hagia_sofia]

If you have 365, then:

=IFS(B2="AVG",C2,B2="FOR",AVERAGE(TAKE(FILTER(D2:V2,D2:V2<>0),,8)),B2="PRE",AVERAGE(TAKE(FILTER(D2:V2,($D$1:$V$1>=W2)*(D2:V2<>0)),,8)))

 

[arthurbr]

For your PRE product something like

=IF(COUNTIF(A1:M1,">0")>=8,AVERAGE(INDEX(FILTER(A1:M1,A1:M1<>0),SEQUENCE(1,8))),AVERAGE(FILTER(A1:M1,A1:M1<>0)))

Adapt ranges as required