SCM poll ignores any exclude regions rules when used with clearcase dynamic view. Looking at the cleacase lshistory command that is executed under the covers, there is no reference to the regex rule.

Example Output from Log :
cleartool lshistory -all -since 25-aug-10.01:50:07utc+0000 -fmt '\"%Nd\" \"%u\" \"%En\" \"%Vn\" \"%e\" \"%o\" \n%c\n' -branch brtype:prj_0505 -nco prj_foo

"20100824.215619" "test" "M:\test_projects\prj_foo\bar\test\build.xml" "\main\prj_0505\1" "create version" "checkin"
Forcing a build

Exclude Regions Rule:
.+prj_foo\\bar
.*$