Thank you very much Victor, 

The following udo works well:

pcode merciVictor(n:i):(k[])
npfield:i = n 
S_chnstr:S[] = init(1)
ctrlArr:k[] = init(npfield)
bar:i[] = [1 ... npfield]
for j in [0 ... npfield-1] do
S_chnstr[j] = sprintf("%.02f_p%d", p1, j+1)
filedvalue:i = pindex(j+1)
bar[j] = filedvalue
chnset(bar[j], S_chnstr[j])
ctrlArr[j] = init(bar[j]) 
od 
l:k init 0
for l in [0 ... npfield-1] do
ctrlArr[l] = chnget(S_chnstr[l])
od
xout(ctrlArr)
endop

if after a quick look you notice something that could cause a bug in future or something else that could help me to progress in Csound, I'm all ears...

Best,

JB

Csound mailing list
Csound@listserv.heanet.ie
https://listserv.heanet.ie/cgi-bin/wa?A0=CSOUND
Send bugs reports to
        https://github.com/csound/csound/issues
Discussions of bugs and features can be posted here