Can I use a wildcard in javascript?

[admin]

I have this on one of my pages

document.forms[0].hiddenFieldName.value = GetCookie('PT_ToDoitem');

but 'PT_ToDoitem' is never 'PT_ToDoitem' it is 'PT_ToDoitemXX'

where XX is a number
and there can be more than one...

how can I get
document.forms[0].hiddenFieldName.value = GetCookie('PT_ToDoitem');

to read all of the 'PT_ToDoitemXX' cookies