Calculates a virtual meter from a formula.
A meter is coded as ID("METERID")
Ariphmetical operators:
() parentheses;
+ plus (a + b);
- minus (a - b);
* multiplycation symbol (a * b);
/ divide symbol (a / b);
Example: (ID("63ac09cb-4e5f-4f3e-bd27-ad8c30bdfc0c") + ID("0209555e-9dc4-4e84-a166-a864488b4b12")) * 2