Search node starts with number and add "_" as start char

I queried to Google Drive and received a xml-Response.

However inside it, there is a tag started with number and my program cannot parse it.

How can I find any node(s) that starts with a number and prefix it with "_" ?

<1092636219480>..</1092636219480> convert to: <_1092636219480>..</_1092636219480>