Obstacle: Lack of Skill
If you lack a specific skill in something the hiring manager is looking for, you can say something to the effect of, "I apologize, I don't have much experience in [skill/program/ect], but I do have experience in [something that translates well to the skill referenced] and I believe my passion for this role will enable me to quickly learn this skill."
Then, if you have some examples to share of how quickly you picked up a similar skill/program, or how you tackled other new (similar) challenges, this can prove that you are more than words and promises. So the most proficient way to convey that you're capable of learning and adapting to new challenges, is to show them how you have succeeded in similar circumstances before.
Example:
"In my previous position as an Administrative Assistant, I quickly adapted to their preferred CRM software, Ontraport. Within three weeks of my start date, I had became an expert user, and my manager asked for my assistance in crafting a weekly training course for the rest of the employees. That led to less down time for the staff, and higher sales in our department. By the end of my first 6 months, I was credited with saving the company over 300 billable hours."
Play down your lack of knowledge, by highlighting your assets. Don't bring up the skill/program that you have limited experience in - only address it if asked directly.
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