Phone number search in global search

We are integrating Genesys CTI with salesforce but we are facing one issue while searching the phone number in global search. From Genesys end we are passing 7 digit phone number to search 10 digit phone number and that searchable but the problem is that if any phone number contains ISD code then that is not searchable. Please find below example to understand the issue

Eg.Without isd code 9876543210 >>> If i enter 6543210 in global search it is searchable

With isd code +919876543210 >>> If i enter 6543210 in global search it is not searchable

Is there any way to search phone number with ISD code in a global search?