Even if your statement works, concatenating 2 memo field in a SQL command is not a good practice. The width of the resulting column is determined by the concatenated data width of the first output record. Information will be lost if data in subsequent concatenations get longer data. You may consider rewriting your statement as:

#define n 254 && or a number smaller than 255 that meets your need
SELECT Padr(m1+m2, n) mResult FROM test INTO CURSOR cResult