The Spearman correlation is just the Pearson correlation of the ranks. For your permutation data, the ranks of the data equals the data themselves, right? So the Spearman correlation of the permutations is identical to regular Pearson computation.
To see this, run the following:
ods select PearsonCorr SpearmanCorr;
proc corr data = perm&n pearson spearman;
run;
Presumably you are familiar with how to compute the Pearson correlation manually. If not, see any textbook, or the doc for the CORR procedure.