Thanks so much for your answer GerineL!!
I do have that option (ie general linear model> repeated measures), but I though it's only for ANOVA, and don't know how to use it for MANOVA. Could you please help me with that? When I do as you said, the first window that opens asks for "within subject factor name" (and number of levels) and then "measure name" (and number of levels).
The "within subject factor name" is obviously clear (before and after manipulation in my study), and so is the "between subjects factor" on the next screen (treatment/placebo in my study). However, the "measure name" is not clear to me. I was assuming that might be the place to enter the variables for my multiple comparisons, but it won't take more than one variable (and I see no other place). Could you please clarify?
Thanks a lot!!
*Perhaps my data file is constructed the wrong way for repeated measures? the within subject variables are in one raw for the first time point, and another raw for the second time point (and codded accordingly), as suits a regular (non repeated-measures) anova. I'm attaching an example file with the same structure as my file (only 5 variables instead of 90).