Scidb convert to upper case lower case


Say I have an array

iquery -aq "build(<val:string>[i = 0:2], '[\'A1Bg\', \'EGFR\', \'x1bG\']', true)"
{i} val
{0} 'A1Bg'
{1} 'EGFR'
{2} 'x1bG'

and I want to convert the strings to all upper case (i.e. the results would look like):

{i} val
{0} 'A1BG'
{1} 'EGFR'
{2} 'X1BG'

Is there any way in which I can do this?

PS: The one option seems to be using rsub from that allows something like

iquery -aq "apply(build(<s:string>[i=0:0,1,0],'{0}[(\'Paul is a serious serious man.\')]',true), r, rsub(s,'s/serious/silly/'))"
{i} s,r
{0} 'Paul is a serious serious man.','Paul is a silly serious man.'

However I am not sure what regex will let me convert from lower-case to upper-case. Based on some online threads (link, link), I tried


but none seem to work.