vlookup?
 

Hi all.
I want to do an if equation that will test if a subtoal value matches a
specific total, when I filter by a column value.
I.e.,
I've filtered my data by the contents of column A to be a specific value--
in this
specific case- 236.

I have a subtotal function:

=subtotal(109,f9:f909)

I then want to do a test that will work for all filtered values depending on
my choice.

=if(f912=....,"ok",WorksheetName!Cell#-f912)

Where the WorksheetName matches the column A value I've chosen in the
filtering.
And the Cell# is a total value I've obtained in a previous calculation on
the WorksheetName.
At first glance it seems that I should use vlookup for this, but I've never
used it before, and what I want seems just complicated enough to confuse
where I should take it next.
So,
1- can Excel do what I'm describing?
2- If so, what should I use?
3- if not, is there something that would work?

Thank you all for your time, and responses/help.
Best.