Because MicroSIP is closed-source, the Control IDs (CIDs) for buttons are not publicly documented. You must use a tool like WinSpy++ or AutoIt Window Info to inspect the buttons and find their IDs every time a new version of MicroSIP is released.
The simplest way to interact with MicroSIP is through command-line arguments. You can call these from cmd , PowerShell, CreateProcess , or any scripting language. microsip api documentation
URI handlers (sip: URIs) As a SIP client, MicroSIP registers as a handler for sip: and sips: URIs on the system. Clicking a sip: link in a browser or invoking a sip: URI from another program will cause the registered SIP client (MicroSIP, if set) to start or place a call to the target address. This is the most common mechanism for integrating softphones into CRM systems, web pages, or click-to-call links. Because MicroSIP is closed-source, the Control IDs (CIDs)