entering data in a field through filtered records only

[Colin@Toyota]

uh.. I guess the title pretty much sums it up... Is there a way to enter data in a text box or something once, and have it applied to all the filtered records?

I have it set up so that we can sort by project number, and it displays only the invoices that havent been assigned to a bill (we recover the expenses form our parent company). I dont want to have to enter the same bill number to each of the filtered records individually.

Thanks