Index match - replace tab reference

Hi, I would like to replace the "Rev'!" in the formula below with a reference to the current workbook, Tab A, cell D19 (with the word "Rev" in it. This is so that I can change the lookup to another tab if needed. Can someone pls advice?

=IFERROR(INDEX(INDIRECT([Database.xlsx]Rev!$C7&"!$A$5:$ZZ$400"),MATCH([Database.xlsx]Rev!$B7,INDIRECT([Database.xlsx]Rev!$C7&"!$A$5:$A$400"),0),MATCH([Database.xlsx]Rev!C$2,INDIRECT([Database.xlsx]Rev!$C7&"!$A$5:$ZZ$5"),0)),"-")

Fast answers need clear examples. Post a small Excel sheet (not a picture) showing realistic & representative sample data WITHOUT confidential information (10-20 rows, not thousands...) and some manually calculated results. Just before posting, scroll down to GO ADVANCED, click, and then scroll down to MANAGE ATTACHMENTS and click again. Now follow the instructions at the top of that screen.