I am attempting to use Vlookup to do a multiple lookup.

I have 7 different worksheets and would like the worksheet names to be one
variable and the worksheet to be a second variable, the vlookup formula is
below. $f$3 is a list of months. I would like to find a way to set the
'a26' to be a variable, so that I can look in different worksheets- depending
on what is input. Each worksheet is an individual person that I need to look
up data on.

=VLOOKUP($F$3,'a26'!$A$2:$J$3639,2,)