I think you'd have to expand the simple command that abr provided to include some scripting glue to do the sort of character replacement you're asking for... Maybe there are other ways - but using the ability to "abuse rename scripts to do other things" in Opus can help you do this... as an example, here's the XML button code for one way you could try this:
Note: there is a variable called delim in the code that is currently set to " " to give the ability to use spaces like you asked as the delimiting character between different filename parts. If you find that you want your searches to include spaces, then you can set this variable to some other value (such as a slash character). Also note that the dialog that appears defaults to pre-populating the input field with whatever is in your clipboard, and "highlights" it for quick overwriting with whatever else you might want to search for. You can change all of that as well to pre-populate the dialog with ANY or NO text at all, and/or to NOT highlight whatever you might use as default search text... At any rate, what I've included below is just an example of little things you can do with Opus that I find useful...
<?xml version="1.0"?>
<button display="both" icon_size="large" label_pos="right">
<label>Test Find Button</label>
<tip>Test Find Button</tip>
<icon1>#findpane</icon1>
<function type="normal">
<instruction>Rename FILEINFO FROM="." TO="{RS|Filename strings to search for:|{clip}}"</instruction>
<instruction>@script vbscript</instruction>
<instruction>Option Explicit</instruction>
<instruction />
<instruction>Dim objShell</instruction>
<instruction>Set objShell = CreateObject("WScript.Shell")</instruction>
<instruction />
<instruction />
<instruction>Function Rename_GetNewName(strFileName, strFilePath, fIsFolder, strOldName, ByRef strNewName)</instruction>
<instruction />
<instruction> Dim delim, wildcard, strCommand, vbQuote</instruction>
<instruction> delim = " "</instruction>
<instruction> wildcard = "*"</instruction>
<instruction> strCommand = ""</instruction>
<instruction> vbQuote = Chr(34)</instruction>
<instruction />
<instruction> strCommand = vbQuote & "C:\Program Files\GPSoftware\Directory Opus\dopusrt.exe" & vbQuote & " /cmd Find in C: D: NAME " & vbQuote & "*" & Replace(strNewName,delim,wildcard) & "*" & vbQuote & " QUIET SHOWRESULTS=tab"</instruction>
<instruction />
<instruction> ' Set strNewName to an empty string so that Opus does not rename the file</instruction>
<instruction> strNewName = ""</instruction>
<instruction />
<instruction> Set objShell = CreateObject("WScript.Shell")</instruction>
<instruction> objShell.Run strCommand, 1, False</instruction>
<instruction />
<instruction> Set objShell = Nothing</instruction>
<instruction />
<instruction>End Function</instruction>
</function>
</button>