Edit text file action and replacing wildcard characters

Hi,

I wish to replace text in a text file and am using Edit Text file action to do this.

I think I need some wildcard character replace option to do what I want.

I need to replace any references like:

<value>C:\Users\******\AppData\Roaming\QSR_Interna tional\CUSTOM.DIC</value>

with

<value>h:\my documents\QSR_International\CUSTOM.DIC</value>

In the same text file, I need to replace any reference to
c:\users\******\documents
with
h:\my documents

where ****** can represent anything, it could be JoeBloggs, JoeBloggs.macaddress, JoeBloggs.macaddress.001 etc
JoeBloggs is the logged in username.

Any ideas how this might be achieved in Edit Text file action or any other way of achieving the same end result?