I've been in the exact same situation as you. I'm a software engineer, and my internship was with a large company that was not in the software industry. They also had me working on Excel macros my first few months, and it got old pretty fast. (You haven't said it explicitly, but I'm assuming the company isn't a software company, or people would write their own macros. Please correct me if I'm totally off base.)
Your biggest obstacle is that most people don't know how a programmer can help them. They don't know what you're capable of, or that they're doing things inefficiently, or what a more efficient way even looks like. They're having you write Excel macros because that's the only way they know to do their job. I promise you they are using Excel for all sorts of things that it's terrible at. You need to find those inefficiencies yourself, come up with a better solution, and then pitch it to any stakeholders. Here are a few suggestions:
Are people passing around spreadsheets that get edited by many people? Do they struggle to get everyone to fill it out the same way? Do they wish they could easily find who changed what and when? Sounds like they need a database!
Are there tasks that involve taking data from one system and putting it into another? (Such as a spreadsheet into a database, a pdf into a client's system, running a bunch of files through some program, etc.) Offer to automate it for them.
Do they use any software made in-house that is buggy or doesn't meet their needs anymore? Fix it.
Some of these projects will be more interesting to code than others, but the most important things you'll learn will have nothing to do with coding at alk. You'll learn to identify problems, design solutions, convince people to buy into your idea, gather requirements, and build relationships. That last one is especially important. As you build trust, people will let you in on what they're doing and will be more likely to take your ideas seriously. Don't disregard small tasks just because they are easy; if you write a small script that saves someone from doing a monotonous task every day, you will become their hero. Build that good will every chance you get!
You may be thinking at this point, "That's great, but how do I figure out what they need help with when no one will give me the time of day?" That is indeed the tricky part, but there are a few ways around it. One option is to chat with people when they are getting their coffee or heating up their lunch. Tell them you're an intern and then ask what they do. Most people are happy to talk about themselves. Show your interest by asking follow-up questions. After they've talked a bit, tell them you've been tasked with making people's work easier, but you don't know where to start. (Don't say more efficient; you don't want to imply that people are working inefficiently.) Ask them if there is any task they have to do regularly that is tedious or if there is in-house software they use that frustrates them. If they seem very receptive, you could even ask to shadow them for half a day to learn more about what they do. You may not get a lot of suggestions at first, but they'll probably come up with ideas over time, so talk to the same people repeatedly.
Another option is to sit in on group meetings, especially if they're working meetings. This is a great way to get to know both the business and the people in it. It's tough to find the right meetings, but again, talking to people will help. Find out what projects people are working on, then try to get in on the ones that sound interesting. Most people are happy to help an intern learn more about what they do. You just have to tell them you're interested.
The last option is to offer to take out the people to lunch that never have time to talk. The feasibility of this one will obviously depend on if you're willing to spend money to get a chance to talk to someone, and maybe the company culture. I think most people will still be flattered that you think they're experts with knowledge worth sharing, though.
**In summary, ** nobody is going to give you an interesting task to work on. You need to be proactive by talking to people and building relationships so that you can find opportunities to show off your skills. Prove that you can be helpful, and you will have people knocking down your door with work. This can be a real opportunity if you play it right. (I'm now a full time employee at the company I interned at, and I have my choice of interesting projects to work on.) Good luck!