I wrote a utility function a while back to do just that:
rfx = @(x,xpnt) [sign(x).*10.^(log10(abs(x))-xpnt), xpnt]; % Anonymous Function Creating Reformatted Number
P1 = 2.331E6;
P2 = 3.215E5;
xpnt = +6;
Out1 = sprintf('Sample A %.7fE%+d', rfx(P1,xpnt))
Out2 = sprintf('Sample A %.7fE%+d', rfx(P2,xpnt))
producing:
Out1 =
'Sample A 2.3310000E+6'
Out2 =
'Sample A 0.3215000E+6'
.
