Input Parameter To Set A Limit

How do I adjust the VB code below so when the user clicks the command button they are prompted to set a limit.
i.e the code only runs til it hits the limit and stop (instead of running until it there are no more x in the columns)

Row 2, Col 9 stores the column numbers (listed as 1, 2,.....100) so thought this could be used in some way.

1. how do i set up the code so a user can enter a parameter value e.g 50 (which is the limit but also includes the values in column number "50")

2. how do i adjust the code so it take the parameter value and stop when it reaches column number "51"...