Hi, AlexMcNee!
First of all welcome to Chandoo's website Excel forums. Thank you for your joining us and glad to have you here.
As a starting point I'd recommend you to read the three first green sticky topics at this forums main page. There you'll find general guidelines about how this site and community operates (introducing yourself, posting files, netiquette rules, and so on).
Among them you're prompted to perform searches within this site before posting, because maybe your question had been answered yet.
Feel free to play with different keywords so as to be led thru a wide variety of articles and posts, and if you don't find anything that solves your problem or guides you towards a solution, you'll always be welcome back here. Tell us what you've done, consider uploading a sample file as recommended, and somebody surely will read your post and help you.
And about your question...
At Solver parameters window you can specify restrictions in the form of Cell/Criteria/Restriction. Give a try to it. No VBA required, just from the main window of Excel.
Regards!