You can't pass a glob by bareword. Try this:
#!/usr/bin/perl
use strict;
use mmm;
local* F;
mmm::fopen( *F, ">tst");
print F "hi";
mmm::fclose *F;
Examine what is said, not who speaks.
"Efficiency is intelligent laziness." -David Dunham
"Think for yourself!" - Abigail
"Memory, processor, disk in that order on the hardware side. Algorithm, algorithm, algorithm on the code side." - tachyon