regularexpressionvalidator in repeater

hi all,

 while i know that for general purposes the repeater is for RO type data views, however i tend to have to use them in more complex situations and actually have to have input controls inside the repeater...ive read a few different things, and have a working custom validator but i wanted to know if it was possible to use the regularexpressionvalidator within the repeater itself.  If so, what would be necessary to get it to validate conditionally on say a txtBox.Text.Length > 0 type condition? thanks -- jp
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