Autosar standard-compilant way to use regex

I need to parse URI-like string. This URI is specific to the project and corresponds to "scheme://path/to/file", where path should be a syntactically correct path to file from filesystem point of view. For this purpose std::regex was used with pattern R"(^(r[o|w])\:\/\/(((?!\$|\~|\.{2,}|\/$).)+)$)".

It works fine but code analyzer complies that it is not compliant as $ character is not belong to the C++ Language Standard basic source character set:

AUTOSAR C++14 A2-3-1 (Required) Only those characters specified in the C++ Language Standard basic source character set shall be used in the source code.

Exception to this rule (according to Autosar Guidelines):

It is permitted to use other characters inside the text of a wide string and a UTF-8 encoded string literal.

wchar_t is prohibited by other rule, although it works with UTF-8 string (but it looks ugly and unreadable in the code, also I'm afraid it is not safe).

Could someone help me with workaround or std::regex here is not the best solution, then what would be better?

Are any other drawbacks of using UTF-8 string literal?

P.S. I need $ to be sure (on parsing phase) that path is not a directory and that it is not contain none of /../, ~, $ , so I can't just skip it.