help with dynamic combo box

Hi, i want to additems to combobox whenever my userform initialize.
I chose to use the list property as i have a very long list and using .additem not as efficient.
What i want my program to do is go to a particular column, then get any data from that column (excluding the column name) and add it to my combo box.
Basically i think my program logic works, but i am not so familiar with excel practices.

main issue is why this 2 lines of code will fail me:

productA = Range("P2", "P3")
comboBox1.List() = productA

Below is the coding i got.

'productA is the list of items i want to add
Dim productA as Variant 
Dim temp As Range
'search for the column with name "Category A"
Set temp = Selection.EntireRow.find("Category A", LookIn:=xlFormulas, lookat:=xlWhole).Offset(1, 0)
'search the column for any filled data and put it in the productA as a list
productA = Range(tp, tp.EntireColumn.find("", LookIn:=xlFormulas, lookat:=xlWhole).Offset(0, 0))
'using list property to add items to combo box
comboBox1.List() = productA

error occurs when my productA list is empty. so i debugged and simplified the code to simulate situation when list should be empty and when list contains 1 item:

Dim productA as Variant 
productA = Range("P2", "P2")
comboBox1.List() = productA

error occurs when list is "empty".

Dim productA as Variant 
productA = Range("P2", "P3")
comboBox1.List() = productA

no error occurs when at least 1 item exist.

Btw the error message is
Run-time error '381'
Could not set the List property. Invalid property array index.

Anyone knows why error occurs when productA is set to Range("P2", "P2")? Thanks alot.

Hello Chia,

Your syntax is wrong in the code below.

Dim productA as Variant 
productA = Range("P2":"P2")
comboBox1.List() = productA

The cell range should be enclosed by a single pair of quotes, like below...

Dim productA as Variant 
productA = Range("P2:P2")
comboBox1.List() = productA

Originally Posted by Leith Ross

Hello Chia,

Your syntax is wrong in the code below.

Dim productA as Variant 
productA = Range("P2":"P2")
comboBox1.List() = productA

The cell range should be enclosed by a single pair of quotes, like below...

Dim productA as Variant 
productA = Range("P2:P2")
comboBox1.List() = productA

Hi thanks for pointing out, that is mistake on my part when i type here. I edited it already.
productA = Range("P2", "P2")
Anyway it still doesnt work with the same error message.