You can create library project in MTB, navigating to File -> New -> Project -> C/C++ -> C/C++ Project -> C Managed Build -> Static Library -> Empty Project.
Use this project to generate .a file you required.
You can create library project in MTB, navigating to File -> New -> Project -> C/C++ -> C/C++ Project -> C Managed Build -> Static Library -> Empty Project.
Use this project to generate .a file you required.