An assignment statement requires a single value:
X = (something that resolves to a single value);
Many of the Call routines do not return single values OR have as one of their parameters the name of a variable to place the result in.
Example:
Call missing ( a, b, c, var1, var2); Sets each of the variables in the parameter list to missing.
call cats(answer, x, y, z); concatenates the variables x, y and z placing the result into Answer. similar to: Answer = cats(x,y,z);
Several call routines provide additional functionality to a similar function such as CALL SCAN that not only returns a "word" but can return the position and length of the returned word in separate variables. (Note multiple results again AND result parameters)
Some other call routines set or remove information used by other functions or call routines such as Call Prxfree frees memory. Some routines set properties for variables such as Call Label. These would not be good candidates for assignments in any case.
So, which specific Call routine are you attempting to use in assignment statements?
