[Gretl-users] data standardization

Hello Gretl communuty, i'm writing for an easy question (I hope). I need to standardize a daily time series based on a monthlly mean and standard deviation (not global mean and standard deviation, this is the main problem). I've tried with matrix but I'm not able to convert a matrix, which is made with an aggregate function (based on monthly mean and stddev), in a variable in my TS with almost 300 obs.