If it's written to win32s, then maybe. Otherwise, almost certainly not.
So, potentially one could deliver the payload, and get the system to try to execute it, only to find that the payload is not compatible with the system executing it.
It'd be kind of interesting... load a page to get a win32s error, or more probably, a straightforward error saying that the program is not an os/2 compatible program.
Now, if the payload was os/2 code, that would be possibly different, but how many of these people are going to know the right parameters to pass to DosExecPgm to tell it to start in an OS/2 session instead of a Win16 session?
Hell, how many of them know about DosExecPgm or DosStartSession to begin with?
Note: pulling the api calls out of the recesses... could be wrong a bit about the name. I'll look it up after I get off work and edit if necessary...