Need help with a EXCEL formula or Function to combine the headers names after trim based on specific the cell data

[bb19august]

[TABLE="class: grid, width: 500"]
<tbody>[TR]
[TD][/TD]
[TD]A[/TD]
[TD]B[/TD]
[TD]C[/TD]
[TD]D[/TD]
[TD]E[/TD]
[TD]F[/TD]
[TD]G[/TD]
[TD]H[/TD]
[TD]I[/TD]
[/TR]
[TR]
[TD]1[/TD]
[TD]TESTF1[/TD]
[TD]TESTF2[/TD]
[TD]TESTF3[/TD]
[TD]TESTF4[/TD]
[TD]TESTR1[/TD]
[TD]TESTR2[/TD]
[TD]TESTR3[/TD]
[TD]TESTR4[/TD]
[TD]RESULT[/TD]
[/TR]
[TR]
[TD]2[/TD]
[TD]YES[/TD]
[TD]NO[/TD]
[TD]YES[/TD]
[TD]NO[/TD]
[TD]YES[/TD]
[TD]NO[/TD]
[TD]YES[/TD]
[TD]YES[/TD]
[TD]F1, F3, R1, R3, R4[/TD]
[/TR]
[TR]
[TD]3[/TD]
[TD]NO[/TD]
[TD][/TD]
[TD]NO[/TD]
[TD][/TD]
[TD]NO[/TD]
[TD]NO[/TD]
[TD][/TD]
[TD][/TD]
[TD]NO RESULT[/TD]
[/TR]
[TR]
[TD]4[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD]NO RESULT[/TD]
[/TR]
</tbody>[/TABLE]

Need help with a formula or function to get a result, if the cell has "YES" or any specific text/NUMBER (above eg. "YES"), which concatenates the header names after trimming it to last two characters and separated by comma and a space.

 

[ExcelElliott]

	A	B	C	D	E	F	G	H	I
TESTF1	TESTF2	TESTF3	TESTF4	TESTR1	TESTR2	TESTR3	TESTR4	RESULT
YES	NO	YES	NO	YES	NO	YES	YES	F1, F3, R1, R3, R4

<colgroup><col style="width: 25pxpx"><col><col><col><col><col><col><col><col><col></colgroup><thead>
</thead><tbody>
[TD="align: center"]1[/TD]

[TD="align: center"]2[/TD]

</tbody>

Sheet2​

[TABLE="width: 85%"]
<tbody>[TR]
[TD]Array Formulas[TABLE="width: 100%"]
<thead>[TR="bgcolor: [URL=https://www.mrexcel.com/forum/usertag.php?do=list&action=hash&hash=DAE7F5]#DAE7F5[/URL] "]
[TH="width: 10px"]Cell[/TH]
[TH="align: left"]Formula[/TH]
[/TR]
</thead><tbody>[TR]
[TH="width: 10px, bgcolor: [URL=https://www.mrexcel.com/forum/usertag.php?do=list&action=hash&hash=DAE7F5]#DAE7F5[/URL] "]I2[/TH]
[TD="align: left"]{=TEXTJOIN(", ",TRUE,IF(A2:H2="Yes",RIGHT(A1:H1,2),""))}[/TD]
[/TR]
</tbody>[/TABLE]
Entered with Ctrl+Shift+Enter. If entered correctly, Excel will surround with curly braces {}.
Note: Do not try and enter the {} manually yourself[/TD]
[/TR]
</tbody>[/TABLE]

This assumes you have Excel 2016, if you do not I'd need a little time to consider an alternative.

 

[bb19august]

Sorry, I have 2013 installed.

 

[bb19august]

I included a UDF for textjoin and was able to get the expected results. Thanks so much for your time and help.