Solver question

Hi everyone, I was wondering if there was a way to program a macro that could help me in my job.

This is the problem: once a week I have to pay providers. Since we try not to pay cash, we select checks from our clients and the only rest in cash.

For example, a provider gives us a bill for $1500.- and I select two checks (one of $750 and the other for $700) and $50.- cash.

My question is: is it posible to make a macro that selects a quantity of checks (form a list) that minimizes the amount of cash to be added?

The problem is that we use checks lower than $2000 for providers and there are some big payments which requiere many of them.

It would save me pretty much time since I have to prepare about 30 payments the same day.

Any Ideas?