How can you load External Library files in QTP?

We can load the external Library files by using 2 ways:
Choose Test > Settings > Choose Resources tab > Choose + button so select the library file > browse and select the library file > click Ok.
We can load the library files using Scripting:
Use executefile function to load library files.
Example:
executefile "C:\Documents and Settings\ukumar\Desktop\Sample.vbs"
x=10
y=5
result=SumOfTwoNumbers(x,y)
msgbox(result)

'Code in External Library file.
'Public function SumOfTwoNumbers(a,b)
'Dim sum
'sum=a+b
'SumOfTwoNumbers=sum
'End Function