If they were consistently named then it would be straightforward to loop through them but if the names are random the only real way to do it would be to put all the textbox names in a loop and go through that.
Code:
Dim arrTextBoxes As Variant
Dim I As Long
arrTextBoxes = Array("Channel1", "CCTV2", "Driving23")
For I = LBound(arrTextBoxes) To UBound(arrTextBoxes)
If Range("A" & I).Value <> "" Then
UserForm1.Controls(arrTextBoxes(I).Value = Range("A" & I).Value
End If
Next I
Note also, that this would only really work if it's possible to refer to the cells to populate the textboxes with some sort of pattern.