Piece together a formulae with text

Hi. I am sure this has been asked
I have a spreadsheet with external Links such as below

VLOOKUP(B2,'C:\Users\Stephen\Downloads\[TEST1.xlsx]Sheet1'!$A$2:$B$17,2,FALSE)

What I want to do replace the TYPE1.xlsx with say a cell value so I can just type say TEST2 in a cell $D$2 and it will tell all the formulas to use the TEST2.xlsx

Example VLOOKUP(B2,'C:\Users\Stephen\Downloads\[$D$2.xlsx]Sheet1'!$A$2:$B$17,2,FALSE) it would help if this can apply to the path as well so i can keep the path in cell $c$2 and retype that in as well.

thanks in advance

PS is there a way to update a spreadsheet after updating the link without opening it. I.e a sort of right click and update