See, if this helps:

set nocount on

declare @ip varchar(255), @cmd varchar(100)

set @cmd = 'ping ' + HOST_NAME()

create table #temptb (grabfield varchar(255))

insert into #temptb exec master.dbo.xp_cmdshell @cmd

select @ip = substring(grabfield,  charindex('[',grabfield)+1,

 charindex(']',grabfield)-charindex('[',grabfield)-1) from #temptb  where left(grabfield,7) = 'Pinging'

print @ip

drop table #temptb

set nocount off