Connect the content of multiple cells to one cell (Excel UDF)

Function lianjie (RAB as range, ISN as Boolean)
'The first parameter is the cell area, which can contain multiple rows and multiple columns. The second parameter is true. The first parameter is a column, the second parameter is false, and the second parameter is a column.
Dim Nr %, NC %, I %, J %, RNG as range
Set RNG = Rab
If ISN = true then
Nr = RNG. Rows. Count
NC = RNG. Columns. Count
Else
NC = RNG. Rows. Count
Nr = RNG. Columns. Count
End if
For I = 1 to NC
For j = 1 to NR
If ISN = true then
Lianjie2 = lianjie2 & RNG (J, I)
Else
Lianjie2 = lianjie2 & RNG (I, j). Value
End if
Next
Next
End Function