MATLAB: Simple For Loop Problem

Hey guysss,
I have a relatively simple problem related to For Loops. Let us say I have this bit of code:
[TPV1.Sig, TPV1.Str] = xlsread('CHAMBER TEST TEMP 4 5 6.xlsx',3);
TPV1.Num = datenum(TPV1.Str);
TPV1.Vec = datevec(TPV1.Num);
The thing is, I have about 10-15 signals that I have to process. Rather than spend a lot of time copying/pasting the code 15 times, I want to write a simple for loop that runs this function over and over again, but stores into different variables. For example:
1st Iteration: Returns: TPV1.Sig, TPV1.Str, TPV1.Num, TPV1.Vec
2nd Iteration Returns: TPV2.Sig, TPV2.Str, TPV2.Num, TPV2.Vec
etc etc
I was thinking setting up the for loop to be like:
for N = 1:15,
       [TPV*N*.Sig, TPV*N*.Str] = xlsread('CHAMBER TEST TEMP 4 5      6.xlsx',3);        TPV*N*.Num = datenum(TPV*N*.Str);       TPV*N*.Vec = datevec(TPV*N*.Num);
The following code is obviously wrong…and I am not sure if I can successfully do this. Any thoughts, anyone??