I was having a simular problem with crons default being sh and wanting to be in csh. I found some where that you should be able to put a line such as SHELL = in your cron tab file but on my system, Solaris 9, this was not allowed. So the best I have found to do is to have the following as the 1st line in the script file cron calls
#!/usr/bin/csh
If it is just one command I want cron to do I do the following:
csh command
thus the command is executed in the csh shell.
Hope this helps.