1) Is it true that the rowsourse format must be equivalent to an Excel
reference, for example

RepEntryBox.RowSource = "'Names'!A1:A5" & NameCount

or using a variable

RepEntryBox.RowSource = "'Names'!A1:A" & NameCount


2) Or is it possible to set this property in a VBA format

Rowsource = Range(cells(1,1), (1,5)) or even

Rowsource = MyRange;... where MyRange is set to a range obj.