Column C contains string IDs with a varying number of blank cells between
each.

Having found the last entry in column E and the latest ID with:

iDoorRow = Sheets("Pages").Cells(Rows.Count, 5).End(xlUp).Row

sDoorName = Sheets("Pages").Cells(iDoorRow, 5)

how can I increment the string (sDoorName) (in this case D02-003) to
D02-004?
Then I can prompt the user to confirm that as the next door or to type in
D03-001 to start the next sequence or whatever.

Francis Hookham