Hi Zen,
For 2G to 3G Reselections,
Concerned Parameters @ 2G end based on Ec/No are;
FDDQMIN
FDDQMINOFF
While based on RSCP;
FDDQOFF
FDDRSCPMIN
And some couple of more are QSI, QSC and QSCI to allow/restrict/modify 2G/3G reselections.
From 3G to 2G reselections;
Based on Ec/No;
sRatSearch and qQualMin
Based on RSCP;
sHcsRat and qRxLevMin
Play around with these Bro !!
Cheers !!