modify label value before query execution

[Uma Vardhini]

Hi All

seeks assistance for.a syntax to modify or string manipulate the label value before query execution

Current

    devicelist=abc1,xyz1, lmn1

    rate(test_gauge{job="xyz" hostname="${devicelist:pipe}"})

 intended modification is to update the hostnames from abc1,xyz1, lmn2 to abc2,xyz2, lmn2. Is there an option to modify the query? I tried with label_replace function and played with regex but no luck

  any help is appreciated