Regular expression on form value

I have a form value that I need to add a regular expression to the end so I can pick up any characters after the form value.

Example if someone enters Jones then I want to make sure the value could also search Jones Jr or Jones Sr.

Basically add a space and any characters a-z to the form value.

Here is my attempt but lost on regular expression part:

REReplace ("form.myvalue","[[:space:]]","Not sure what the regular expression would be here?","ALL")