yes u can do it through the translation pattren but the translation depends on how u configured ur callmanager with ur pstn gateway
in otherwords if it is h323/mgcp gateway how many digits the gateway send to the callmanager, The Significant Digits field determines the number of digits, of an incoming dialed number, that will be used by CallManager. CallManager counts from right to left, so if the number entered in this field is four and the digits received are 8105559090, 810555 will be removed and only 9090 will be used to determine the destination of this call.
so lets say the pstn send u 8105559090 and u made the significant digits to 4 so the callmanger will use the 9090 as the incoming call
now create a translation pattren with pattren 9090 and in the buttom make the called number trnsformation to 1003
so this call will be trnaslated to 1003
make sure that the gateway has access this transaltion-patttren and the translation pattren has access to the intended ip phone
this access controled through partiions and CSS
see this link as well
http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/admin/5_1_3/ccmcfg/b03txpat.html
for ur DID u could od it like
set the significant digit to 4 on the gateway setting then make this translation:
6470 to 1003
if u wanna make matching for all range u need to make consistancy between the DID and the internal numbers like:
64XX to 10XX
the internal numbers DID will lokk like
1070,1071 to 1099
which is better than maping one by one
good luck
if helpful rate