Ok, got a little script whipped up for you. I put it over in the iControl Codeshare under PerlSetMonitorProperty
http://devcentral.f5.com/wiki/default.aspx/iControl/PerlSetMonitorProperty.html
Click here
The usage is as follows
$ .\PerlSetMonitorProperty.pl bigip 443 user pass
HTTP Monitor Templates
----------------------
my_http
http
$ .\PerlSetMonitorProperty.pl bigip 443 user pass my_http
STYPE_SEND = GET /
STYPE_RECEIVE = hi there
STYPE_USERNAME =
STYPE_PASSWORD =
$ .\PerlSetMonitorProperty.pl bigip 443 user pass my_http STYPE_RECEIVE "Success"
STYPE_SEND = GET /
STYPE_RECEIVE = Success
STYPE_USERNAME =
STYPE_PASSWORD =
Hope this gets you going in the right direction.
-Joe