Here is the function, save this as numberformat_french.cfm somewhere accessible to your application:
CODE
<cftry>
<cffunction name="numberformat_french" returntype="string" output="false">
<cfargument name="mynum" type="numeric" default="0" required="yes">
<!--- convert to valid number format string --->
<cfset mynum=numberformat(mynum,"9,999.99")>
<!--- replace the commas with spaces --->
<cfset mynum=replace(mynum,","," ","all")>
<!--- replace decimals with commas --->
<cfset mynum=replace(mynum,".",",","all")>
<cfreturn mynum>
</cffunction>
<cfcatch type="any">
<cfset mynum = 0>
</cfcatch>
</cftry>
Then, code your CFM page like this:
CODE
<cfinclude template="/_udf/numberformat_french.cfm">
<cfoutput>#numberformat_french(10000.12)#</cfoutput>
And you should be set.
If you haven't used UDFs, this is a perfect example to use them. If you have to do this a lot, then put the include in your application.cfm folder or inside another include that is designed to be called on pages where this functionality is required.
Once the include is called all you have to do is wrap your number in the function format and be sure that is somewhere in a <cfoutput>.
Thats quick and dirty solution - hope that helps.