You may have to break up your formula to look at left side (up to the postal code) and then concatenate the right side (postal code).

e.g.

=PROPER(LEFT(INDEX('\\ORACLE-B\Trackers\HUB Files\HUB\[HUB.xls]Hub'!$A$4:$M$2533,MATCH(E12,'\\ORACLE-B\Trackers\HUB Files\HUB\[HUB.xls]Hub'!$A$4:$A$2533,FALSE),4),LEN(INDEX('\\ORACLE-B\Trackers\HUB Files\HUB\[HUB.xls]Hub'!$A$4:$M$2533,MATCH(E12,'\\ORACLE-B\Trackers\HUB Files\HUB\[HUB.xls]Hub'!$A$4:$A$2533,FALSE),4)-8))&RIGHT((INDEX('\\ORACLE-B\Trackers\HUB Files\HUB\[HUB.xls]Hub'!$A$4:$M$2533,MATCH(E12,'\\ORACLE-B\Trackers\HUB Files\HUB\[HUB.xls]Hub'!$A$4:$A$2533,FALSE),4)),8))
Or you can separate the originals into 2 side by side columns and concatenate them in your formula using proper for one side only