Split phone number and string

[ghjk]

I want to split phone number and string.
ex:94778485899
I want to Extract only 778485899 part from the phone number
ex: START45.99
Want to remove START from the string and get the floating point number only.Floating point number vary from time to time. May be 23.88, 8.0.
This is my code for splitting the floating point number. But it gets only 5 numbers.
ex:When i have START888.66 It gets only 888.6.So could some one help me to do the splitting on these string and number.
[PHP]
$mnn = $mn[0];//START888.66
$RR = str_split($mnn, 5);
$RR1 = $RR{0}//STSRT
$RR2 = $RR{1};//888.6
[/PHP]

[ghjk]

I have done. Best solution is substr

[pbmods]

You might want to take a look at preg_match_all() (http://php.net/preg_match_all).