=OFFSET(INDIRECT("'Lists'!R2C" & MATCH("Header1",Lists!R1,0),FALSE), 0, 0,
COUNTA(INDIRECT("'Lists'!C" & MATCH("Header1",Lists!R1,0),FALSE))-1, 1)

The above allows me to define a dynamic range wherever "Header1" is in on
the sheet "Lists". Is this the most efficient/best way?

TIA