Varying position size for more than one ticker

I would like to implement a system which invests the equity in a couple of tickers (e.g. 3). The position size for each one should be determined in a certain frequency (e.g. per week) and an re-allocation should then happen. Is it possible to do that, more concretly to set the postion size individually in dependence of ticker and the looping reallocation date, please?

Thank you