Dear all,

I'm sorry if this is any way wrong or incorrect or if I am unknowingly breaking rules, as this is my first post.
However, I really need help with a problem I have been stuck on for over a week and I simply cannot find a solution.
The issue is really complicated and no matter how many different ways of doing each individual task element of it, I simply am not able to compile it into a working formula.

It's quite a long explanation of the problem, so please do bear with me.

First off, this problem is based on two data tables.
1) The first is a 6 column by 300 row data table of which the 4th and 6th columns will be required in this formula.
2) The second is an 11 column by 40,000 row data table, in which we will be concerned with all columns.

The two tables are on separate pages (when I finish the whole project they will all be integrated into one page), with the former on Sheet1 and the latter on Sheet2

The key is to find the average on an array of values based on criteria. The criteria is checking whether the the 4th column in the former table contains one of ten text strings. It need not have all ten text strings, simply must have one or more of the ten text strings within it.

The ten text strings are individually calculated in the first ten columns of the latter table, and this formula is entered on the 11th column. So for example, A1:J1 will contain individual text strings, e.g "La" or something similar.

What we are trying to do is find out which of the rows in the fourth column of the former table has one or more of the ten text strings within, and then to create an average of all the figures in the corresponding rows of the sixth column.

So if La can be found in the fifth, tenth and eleventh rows, I want to find that out and then average out the values in the sixth column of the former data table at the fifth, tenth and eleventh rows.

Currently my formula looks a bit like this, but it's not working, it always returns a #DIV/0 error.
{=AVERAGE(IF(ISNUMBER(MATCH(Sheet1!$D$1:$D$300,{"*"&$A1&"*","*"&$B1&"*","*"&$C1&"*","*"&$D1&"*","*"&$E1&"*","*"&$F1&"*","*"&$G1&"*","*"&$H1&"*","*"&$I1&"*","*"&$J1&"*",},0))="TRUE",Sheet1!$E$1:$E$300))}

Thank you in advance for all and any help!

Martins1