SAS - how to find variable name in string which is similar to a specified sub-string

I want to find if a variable exisits in a string (&fixed) and if so, which word number.

%LET fixed = %STR(variable1 region1 variable3);

%IF %INDEX(&fixed, regio) %THEN
  %DO;
    %LET regioxc = %SCAN(&fixed, %SYSFUNC(FIND(&fixed, regio)));
  %END;

I want to create a macro variable called regioxc, which could be equal to either region1 one time, and the next time the macro is run it could be equal to regiodc, or something else (always with the beginning string 'regio'), if that is the region variable specified within the &fixed string. This only works if the regio variable is specified first within the &fixed string, but in this case it is the second variable, so this does not work. I cannot find a robust method of creating the variable (word) count value from the &fixed string to be able to use the scan function. I know it should be 2, in this case. Any help here would be much appreciaited.

via Chebli Mohamed