Index / Match to find column header

[Real_Sooner]

I have a sheet named 'Diff' that has ID in column A and Difference in column K.
I have another sheet named 'Udata' that has ID in column A and amounts in columns B:JG.
I am trying to look up the code in row 3 (column header) of the UData tab, based on the ID number and Difference from the Diff tab, but keep getting the error N/A. Help Please!

Example:
Diff Tab
A167964 = 1234
K167964= 5.22

Udata tab
A4 = 1234
BG3 = SSHT-R
BG4 = 5.22

Need a formula for cell L167964 on the Diff tab that gives me a result of "SSHT-R"

BONUS: What if there are 2 or more columns in B:JG that have the number 5.22? Is there a way to get multiple results? Thanks in advance!

 

[AhoyNC]

See if this example helps. Change ranges to match your data.
This is an array formula and must be entered with CTRL-SHIFT-ENTER.

Excel Workbook
	A	B	C
1	Find
2	ID	1234
3	Diff	5.22
4
5	Header(s)
6	Header3	SSHT-R
Diff

Excel Workbook
	A	B	C	D	E	F	G	H	I
3	ID	Header1	Header2	Header3	Header4	SSHT-R	Header5	Header6	Header7
4	5679	3.25	5.22	5.00	9.24	9.00	8.00	5.00	4.00
5	2525	3.00	6.00	4.00	3.00	2.00	9.00	6.00	9.00
6	1232	9.00	7.00	6.00	7.00	7.00	2.00	0.00	5.00
7	1234	3.25	0.00	5.22	6.00	5.22	4.00	5.25	5.00
8	5648	0	4.78	5.23	3.00	6.89	6.00	9.00	8.00
UData

 

[AhoyNC]

In the formula above, drag across columns as needed to get all results.